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Partial tear down of Willsenton R8


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I am not an expert on tube amp like many on this forum however writing this blog to help those who are thinking of buying Willsenton R8 or those who owns it and want to know bit more about it. I am no

The Melz 1578s arrived today and boy are they neat! For those that don't know, they were developed for Soviet era nuclear facilities and military applications. Here's a pic of them warming up in the R

Channels unbalance. Hello to everyone, I'm new to this nice forum, discovered looking for info about R8 tubes rolling and its quality improvement.  I’d like to share my experience about channels

😂

The smell was super strong out of the box, these things clearly are being packed not long after assembly. The paint is dry but not aired right out 😅

 

Mine lasted about a day then went away, the boxes are in the garage, I haven't checked them but I suspect the fumes would be in the foam and cardboards after a 5week boat ride couped up and sealed.. 

 

 

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Hi All..

Upto about a dozen hours now and all is good.

I am very happy with lows, I am finding the mids/highs  a bit forward and even maybe brittle, maybe even distored is a good word but its not true distortion. More so a sound presentation that is not my preference.  

Further burn in might settle this down but reading around it could also be the KT88 doing what they're designed to do.  Maybe they're not as forgiving with hard rock and metal as I was aiming for.  That small and very fixable thing aside  I have no humming or any other noise to raise any unwanted suspicions.   Its great. 

I have read around online with regard to tubes  to allow about 40hrs of burn in but am wondering if the KT88 will settle to the sound signature I like or if I need/should consider rolling these out sooner than my initial plan?

To provide clarity I am after a fat "laid back" sound.  Lows I like to have some kick,  mids dont need to be overly pronounced but a flat mid quite ok.. With highs, a sweeter sound, nothing overly exaggerated or glassy, even slightly rolled off is better than bright!!!  I am new to this rolling caper and also have some confusion about rolling the pre tubes or the power tubes first and which is going to have influence.

 

Based on reading through this thread and the rolling already done I am not sure the KT77 or 6550 are quite what I am after but also happy to advised otherwise.

I am thinking maybe the Tung Sol EL34B will be good. Most suggest its mids are clean and full, plenty of bass and slightly softer but well detailed top end all without being a forwardly accentuated presentation. 

For the 6SN7 I am thinking the Tung Sol GTB or the EHGold Pin both seem to be well regarded - not sure of any distinct SQ signature being vastly different.

For the 6SL7 I am thinking the Tung Sol or the Sovtek, again, pretty well regarded and not much to suggest much difference. 

 

Whilst I wont be pulling the trigger on any of the above this week or so I am happy to get some opinion on the above options.  I can keep playing music with all the stock tubes and if still itching for change I can make some purchases.

 

Cheers.

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4 minutes ago, 08Boss302 said:

Hi All..

Upto about a dozen hours now and all is good.

I am very happy with lows, I am finding the mids/highs  a bit forward and even maybe brittle, maybe even distored is a good word but its not true distortion. More so a sound presentation that is not my preference.  

Further burn in might settle this down but reading around it could also be the KT88 doing what they're designed to do.  Maybe they're not as forgiving with hard rock and metal as I was aiming for.  That small and very fixable thing aside  I have no humming or any other noise to raise any unwanted suspicions.   Its great. 

I have read around online with regard to tubes  to allow about 40hrs of burn in but am wondering if the KT88 will settle to the sound signature I like or if I need/should consider rolling these out sooner than my initial plan?

To provide clarity I am after a fat "laid back" sound.  Lows I like to have some kick,  mids dont need to be overly pronounced but a flat mid quite ok.. With highs, a sweeter sound, nothing overly exaggerated or glassy, even slightly rolled off is better than bright!!!  I am new to this rolling caper and also have some confusion about rolling the pre tubes or the power tubes first and which is going to have influence.

 

Based on reading through this thread and the rolling already done I am not sure the KT77 or 6550 are quite what I am after but also happy to advised otherwise.

I am thinking maybe the Tung Sol EL34B will be good. Most suggest its mids are clean and full, plenty of bass and slightly softer but well detailed top end all without being a forwardly accentuated presentation. 

For the 6SN7 I am thinking the Tung Sol GTB or the EHGold Pin both seem to be well regarded - not sure of any distinct SQ signature being vastly different.

For the 6SL7 I am thinking the Tung Sol or the Sovtek, again, pretty well regarded and not much to suggest much difference. 

 

Whilst I wont be pulling the trigger on any of the above this week or so I am happy to get some opinion on the above options.  I can keep playing music with all the stock tubes and if still itching for change I can make some purchases.

 

Cheers.

 

Here is my observation.....

 

Tung Sol EL34 has very good base and excellent mids but highs are rolled off

KT77 has too much mid but I haven't broken them in to check further

Tung Sol 6SN7 is an excellent current production tube which is almost at par with NOS tubes.

There is nothing in current production for 6SL7 which can match NOS tubes (except . Don't even  bother to try Sovtek, it is same chinese tube what you have, just re-branded.

 

Stock KT88 are good tubes and suits to the taste what you mentioned, I think you will get the sound what you want by rolling pre-amp tubes. If you go to any EL34 family tube, mids will be pronounced one and you will loose base (except TS EL34B).

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@08Boss302 The nice thing, IMO, is that this amp can be tweaked to accommodate most preferences. First, what speakers do you use and what is/are your sources? I definitely recommend waiting a few weeks to make any moves. The character of the amp will change, I promise!

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30 minutes ago, Atmaj said:

 

Here is my observation.....

 

Tung Sol EL34 has very good base and excellent mids but highs are rolled off

KT77 has too much mid but I haven't broken them in to check further

Tung Sol 6SN7 is an excellent current production tube which is almost at par with NOS tubes.

There is nothing in current production for 6SL7 which can match NOS tubes (except . Don't even  bother to try Sovtek, it is same chinese tube what you have, just re-branded.

 

Stock KT88 are good tubes and suits to the taste what you mentioned, I think you will get the sound what you want by rolling pre-amp tubes. If you go to any EL34 family tube, mids will be pronounced one and you will loose base (except TS EL34B).

 

Cheers for this . So I am on the right track but maybe hold off on the power tubes and mess about a bit with the pre tubes first off.  The 6SN7 seems sorted but the 6SL7 which I'll roll the dice on TS or cough up for NOS.    My pocket says the TS will be the first step though.

 

29 minutes ago, echorec said:

@08Boss302 The nice thing, IMO, is that this amp can be tweaked to accommodate most preferences. First, what speakers do you use and what is/are your sources? I definitely recommend waiting a few weeks to make any moves. The character of the amp will change, I promise!

 

thank you!

yes, I certainly will wait a few weeks, I have a number or sources.  Speakers re KEF Q950 so probably on the slightly warmer side of neutral IMO (which I prefer) The stock tubes actually sound really nice with digital (CD or streaming) it seems they are bit more fussy with vinyl source, this could also be in part to the phono stage and carts I use, but with my other amp (Vincent SV237mk) vinyl sounds very nice.  I rolled the pre tubes in that but its a hybrid amp.  More than enjoying things at the moment and will give it time but if it still has that toppy almost distorted sound whilst playing vinyl i'll look to make some quick changes.

 

I will play some CD's on loop and then stream for a few hours back to back over the next few days and weekend. I'd say this time next week i'll well and truly have passed the 40hr mark, I should get a good impression then.

 

I've tried TR/UL mode too, I do prefer TR mode for most things i've played, UL seems to get quite grainy but again I have read this can be a characteristic of the KT88 and new tubes too. Some burn in will most certainly alter this imaging.

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A little update on my R8 problem. Mr. Lee was very responsive (at first) and believes that the bias potentiometer for V1 is faulty (I also got the impression that I am not the first person to have this particular issue). He kindly offered to send the replacement part, however communication has stopped on his end, so I'm not sure if or when I will get the replacement part. My last email was simply asking how long I should expect the part to arrive, and I also offered to pay for express shipping to get it to me faster, but he hasn't replied (it's been about 1 week). So I don't know what to expect, but I wish there was better with communication...

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@Atmaj thanks for sharing your observations !

did you happen to try tungsol reissue 6sl7 gold pins they are 80 dollars each ? Or better to stick with NOS for 6sl7 ?

 

I think those stock tubes are actually Russian sovtek , I compared them side by side they are identical

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1 hour ago, demoiree said:

@Atmaj thanks for sharing your observations !

did you happen to try tungsol reissue 6sl7 gold pins they are 80 dollars each ? Or better to stick with NOS for 6sl7 ?

 

I think those stock tubes are actually Russian sovtek , I compared them side by side they are identical

No, I did not bother to check those. When I compared those with normal TS 6SL7, they are same with construction. The only difference I saw was the golden pin. Also NOS Sylvania were cheaper.

 

Regarding stock tube, I mentioned about that in my observation post above. They are not Russian, Sovtek are Chinese tunes. 😉

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5 hours ago, echorec said:

A little update on my R8 problem. Mr. Lee was very responsive (at first) and believes that the bias potentiometer for V1 is faulty (I also got the impression that I am not the first person to have this particular issue). He kindly offered to send the replacement part, however communication has stopped on his end, so I'm not sure if or when I will get the replacement part. My last email was simply asking how long I should expect the part to arrive, and I also offered to pay for express shipping to get it to me faster, but he hasn't replied (it's been about 1 week). So I don't know what to expect, but I wish there was better with communication...

I hope this improves for you.

Yong has been great with all comms I have had with him but that said, I have not had the issue you have had.  I think given the buzz about this amp, the Muzishare, Line Magnetic, JungSong  and some of the SoundArtist stuff available from him that he'd be all over making sure any issues are corrected swiftly.  With the audiophile world and also the reach of the internet any negativity will run rampant...not to mention there is arguably many folk out there that that are waiting to rant "I told you so" on ChiFi products, even though issues arise in products manufactured in all corners of the world.  The worst customer service I have ever experienced was with Sony, so I am certainly no believer that the bigger brand offers the better follow up, matter of fact, IME the bigger the brand the bigger bully and snub you are likely to receive.

 

Keep us upto date on this one, it is a good yard stick to gain perspective on after sales warranty.

 

I wonder if half the issue with the R8 is the demand and a few are slipping past QC to cater?

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6 hours ago, echorec said:

but he hasn't replied (it's been about 1 week). So I don't know what to expect, but I wish there was better with communication...

 

I hear what you're saying. And have encountered the same thing. He is usually responsive to emails but there will be periods of silence esp if the diagnosis is already done. He might have already sent out the part. 

 

I'm guessing a lot of things are going through him and there's many of us. I sometimes get the feeling he's trying to catch up coz there were some confusion in his email reply to me. Sometimes he will email in the wee hours of the morning and weekends. I think he's doing what he can. Guessing everyone would appreciate the customer offering help but it might then mean an extra step or so in the process on his side when he's trying to standardise everything. 

 

 

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I'm sure things will work out fine. I'm just anxious. It's only a testament to how much I love this amp though.

 

@Atmaj Do you happen to know the specs of the R8's bias trim pots? (I can't read schematics). I wonder if these are available through an online vendor or if they are proprietary to the Willsenton factory.

 

 

 

 

R8-Trim-Pot.jpg

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I was looking from the wrong angle. It's 22k. Does anyone recognize the company logo on the pot? It looks like planet Saturn.

 

 

R8-Pot-2.jpg

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If you guys are looking for a great 6SL7 type of tube that won't cos a fortune, look at the MELZ 6H9C (6SL7) metal base from the Moscow factory 'MELZ' from the 1950's. They are miles better that the standard Russian ones, very refined sounding, spacious and smooth with plenty of detail.

 

Some prices have skyrocketed but if you hunt down some from Russian or Ukrainian sellers they can still be gotten pretty cheap.

 

They look like these

20201003_122217.jpg.bbe0c0f4abed43e386938f0b4fcf7856.jpg.09e695a23746b21d6763ddd3e30fd794.jpg

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21 hours ago, echorec said:

I was looking from the wrong angle. It's 22k. Does anyone recognize the company logo on the pot? It looks like planet Saturn.

 

 

R8-Pot-2.jpg

 

Yes it is 22K but needs to open up that board to exactly find out the the type. They also come as Linear and Logarithmic. I will reckon to wait for Yong to send the replacement one or take to a tech close to you.

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Quick update on my warranty through China Hifi - Yong emailed me today with tracking for my replacement part. The part is shipping from Los Angeles (I'm in the US) which is great because it should get here quickly. I believe he uses his US distributor for all US related issues, which is more efficient for everyone. Anyway, so far so good!

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  • 2 weeks later...

I received the replacement part from Yong yesterday! Instead of sending a potentiometer, he sent me the entire populated bias circuit board with leads attached, so I was quite pleased. I took the amp into my local HiFi shop yesterday and was able to pick it up this morning. Everything sounds good, so hopefully the problem doesn't come up again. I kept the old bias PCB in case I need any of those parts later. The labor cost to replace the bias circuit and bench test was $125 USD, so my R8's cost definitely went up. Still better than having to ship this beast to someone elsewhere and deal with that whole headache. A word of advice: if you have any issues with your amp, be patient with Yong. I think he is absolutely slammed with emails each day. He will get back to you and he will help you make things right, but sometimes he isn't as responsive as many of us are used to. I read somewhere else that he has apparently hired some people to help him, so that is good news if true.

 

A couple of interesting comments from the service guy (This is one of the best guys in our State. He's been building and servicing tube amps for a very long time and works with a lot of high level and boutique HiFi equipment). His first comment was how he thought the design and layout was really good on this amp. He told me the solder job was "a bit sloppy" as he had to touch up several spots inside the amp that could have potentially turned into future problems. His final comment was that he thought the amp sounded "very beautiful and musical".

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Good to know that you got the replacement and the issue is resolved.

 

$125 USD for replacing the bias board 😵  Gosh, that is too much. I would have done it for free but we are at opposite end of world  🤣

 

He is spot on with soldering but it is far far better than other Chinese product. I in-fact did not have to touch up any solder joints in my amp. Being manual soldering, it also depends upon which worker in production line soldered yours and who soldered mine.

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Channels unbalance.

Hello to everyone, I'm new to this nice forum, discovered looking for info about R8 tubes rolling and its quality improvement.  I’d like to share my experience about channels unbalance problem also reported from some of you.  My Willsenton too showed a little unbalance in favour of left channel. At first I was wrongly thinking about not symmetrical tubes gain or a poor quality volume potentiometer.  The root cause was instead an internal wrong connection of the left output transformer to the output plugs.  The left 8 ohm and 4 ohm connections  were exchanged,  The result was the right loudspeaker connected to the 4 ohm R8 output and the left loudspeaker connected to the 8 ohm R8 output,  the consequent bigger voltage output on the left channel was the unbalance root cause.  That is an easy assembling error cause the 2 wires connecting 8 & 4 ohm plugs are both brown color (at least in my unit).

How to check if your output transformers are wrongly  connected to the rear plugs?  easy, by a tester you can measure the resistance between the 8ohm plug / Black plug   and the 4ohm plug / Black plugs: the first resistance must be higher than the latter.   Now my  R8 is well channel balanced as confirmed also by oscilloscope acquisition.

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25 minutes ago, F_Fabio said:

Channels unbalance.

Hello to everyone, I'm new to this nice forum, discovered looking for info about R8 tubes rolling and its quality improvement.  I’d like to share my experience about channels unbalance problem also reported from some of you.  My Willsenton too showed a little unbalance in favour of left channel. At first I was wrongly thinking about not symmetrical tubes gain or a poor quality volume potentiometer.  The root cause was instead an internal wrong connection of the left output transformer to the output plugs.  The left 8 ohm and 4 ohm connections  were exchanged,  The result was the right loudspeaker connected to the 4 ohm R8 output and the left loudspeaker connected to the 8 ohm R8 output,  the consequent bigger voltage output on the left channel was the unbalance root cause.  That is an easy assembling error cause the 2 wires connecting 8 & 4 ohm plugs are both brown color (at least in my unit).

How to check if your output transformers are wrongly  connected to the rear plugs?  easy, by a tester you can measure the resistance between the 8ohm plug / Black plug   and the 4ohm plug / Black plugs: the first resistance must be higher than the latter.   Now my  R8 is well channel balanced as confirmed also by oscilloscope acquisition.

Hi Fabio

Welcome to the forum and thank you for the information.  Thankfully mine seems fine with balance but it seems a few people have had some quirky issues.

Did you roll the tubes?

How are you enjoying it now and what tubes if you rolled did you go with?

 

 

 

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40 minutes ago, F_Fabio said:

Channels unbalance.

Hello to everyone, I'm new to this nice forum, discovered looking for info about R8 tubes rolling and its quality improvement.  I’d like to share my experience about channels unbalance problem also reported from some of you.  My Willsenton too showed a little unbalance in favour of left channel. At first I was wrongly thinking about not symmetrical tubes gain or a poor quality volume potentiometer.  The root cause was instead an internal wrong connection of the left output transformer to the output plugs.  The left 8 ohm and 4 ohm connections  were exchanged,  The result was the right loudspeaker connected to the 4 ohm R8 output and the left loudspeaker connected to the 8 ohm R8 output,  the consequent bigger voltage output on the left channel was the unbalance root cause.  That is an easy assembling error cause the 2 wires connecting 8 & 4 ohm plugs are both brown color (at least in my unit).

How to check if your output transformers are wrongly  connected to the rear plugs?  easy, by a tester you can measure the resistance between the 8ohm plug / Black plug   and the 4ohm plug / Black plugs: the first resistance must be higher than the latter.   Now my  R8 is well channel balanced as confirmed also by oscilloscope acquisition.

 

Welcome @F_Fabio ! This is excellent information! Can you give a little more detail on how to test this? I have a multimeter, and I'm assuming I can test it on the back terminals, correct? Does the amplifier need to be on? And do I need to remove the speaker wire? etc.. Thank you!

Edited by echorec
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Hi,  here more details.

R8 must switched OFF  !!

Disconnect both the loudspeakers

Test ohm values directly connecting the tester to the back terminals

Verify both channels,  8 ohm terminals resistance must be higher than 4 ohm resistance,  values must be very similar on both channels.

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@F_Fabio I just tried it and I don't think my multimeter is sensitive enough. The lowest resistance setting is 2K and I get "0" reading. It has the following settings: 2M, 200K, 20K, 2K, and a symbol that looks like this:   ->|-

 

I am currently using the 8ohm taps for my speakers. I guess I could simply change the one speaker (the perceived quieter one) to the 4ohm and see if I can hear a difference in balance. Is there any harm to the amplifier if I do this temporarily? Thanks!

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You are right. You have to utilize tester able to measure  values  around or below  1 ohm

Yes, try to connect the single speaker to the 4 ohm terminal  and check the balance,  no harm at all for the R8.

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@F_Fabio I was able to borrow my neighbors multimeter, which has better sensitivity. The 8ohm taps both tests at 8ohm and both 4 ohm taps both tests at 6ohm.

 

I also don't notice any channel imbalance since I had the new bias circuit installed this week, so I think everything is good now.

 

Thanks again for the information!

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Quite strange and high resistance value..   my R8  output transformer resistance is about 0, 48 ohm  measured   @ 4ohm rear terminals.   Could be nice to have data from other R8 owner..

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2 minutes ago, F_Fabio said:

Quite strange and high resistance value..   my R8  output transformer resistance is about 0, 48 ohm  measured   @ 4ohm rear terminals.   Could be nice to have data from other R8 owner..

Thanks @F_Fabio and welcome. Interesting to hear about the issue with the wiring. Can't say I have a problem with the imbalance but I had to experiment coz my speakers are 6 ohms.

 

Folks say to play around the 4 and 8 ohm outputs and see which sounded better. I'm now on the 4 ohm output and I recalled the 8ohm output sounded softer and the soundstage was smaller. 


Hopefully your advice can help solve the imbalance others are facing. 

 

 

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Hi,  Connecting  the speakers to the R8  4 ohm output terminals  will increase the  sound quality ,    that is due to the lower output impedance of the 4 ohm output.  Low output  resistance means better control of the speakers and double output current  (although  you won't reach the nominal R8 output power if you have 8 ohm speakers).  I'm on the 4 ohm output too.

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Interesting. I have been using the 8ohm tap with my 6ohm speakers. For me, the 8ohm sounded better (slightly bigger soundstage and slightly more punch), so perhaps it will vary from speaker to speaker.

 

Btw, Thomas and Stereo just published his video on the R8:

 

 

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Thanks @echorec for sharing the link. A pleasant surprise this morning. Nice review with his signature stories and weird analogies. While a bit disappointing that he didn't discuss tube rolling in this video but great that he's generous enough to make a separate video on it. 

 

He even spoke about the preamp bypass which @Atmaj highlighted. 

 

I took the plunge 2 weeks ago and purchased some tungsols. for the pretubes. Very big difference switching between the standard 6SL7s, shuguangs and tungsols. The difference can be further tuned with the KT88 and EL34s. 

 

This is a dangerous amp for tube rolling. I might make one more tube purchase based on his next video if it make sense. But that's it.. I wanna save for another speaker. 

 

 

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34 minutes ago, 2Dculture said:

This is a dangerous amp for tube rolling. I might make one more tube purchase based on his next video if it make sense. But that's it.. I wanna save for another speaker.

 

Dangerous, but so much fun! I'm really excited for his tube rolling video. He mentioned elsewhere that either Mr. Vintage or Mr. Kanta used some VERY expensive NOS tubes to see what it was capable of. That will be a fun video.

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16 minutes ago, echorec said:

He mentioned elsewhere that either Mr. Vintage or Mr. Kanta used some VERY expensive NOS tubes to see what it was capable of. That will be a fun video.

Oh yes.. I remember that. There was a video or a photo showing the different tubes one of them had purchased. 

 

It is fun.. esp if you want to shape the sound.

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I have done plenty of tube rolling including new and NOS and I think I am done with it 🙃

 

It was a bit disappointing that Thomas did not use the snaps I sent him. He liked this post and said that he may use in his video.

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2 hours ago, Atmaj said:

I have done plenty of tube rolling including new and NOS and I think I am done with it 🙃

 

I'm pretty there already. Just seeing what else Thomas will recommend. I noticed he showed the Shuguang 6SL7 in the video. i wonder if its a sign of things to come. 

 

My priority now is a pre-loved Klipsch. Sonus Faber are great but I realise its not that great for music that has urgency. 

 

Ya.. he didn't mention or showed your diagrams. I was expecting some reference to you whenever he mentioned a subscriber. Would be nice. But I think we learnt more about the R8 in your journey tearing apart the system than his review. So thanks for your sharing and importantly, starting this thread Mr OP!

 

His review was nice but it was more about affirmation about our purchase, whether it was good or bad. I like my purchase so I know its good but would be nice if some kind of influencer who have heard more gear than me likes it as well. 

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Great review, a few weeks back, maybe even over a month when Thomas first posted he was going to review the R8 I got the vibe he didnt enjoy it as he illuded to a lot of NOS tube rolling and the massive differences it made and the cost of NOS tubes vs the cost of the amp...whilst I have no insight I am kind of expecting that to be a feature in his follow up video.  Having said that, I could be way off and NOS tubes on any amp irrespective of purchase price add up quick.

I really enjoy his channel, I find him one of the best on YouTube in all his reviews. I like his stories and the way he goes about explaining each piece of equipment he reviews. I also like how his reviews are quite real world gear, whether thats intentional or chance I dont know but it draws me to his channel frequently looking for his next review.

 

Anyway, Good to see another positive review of this amp.  The price of the amp seems to be a point often referenced, which keeps indicating to me it is competetive well beyond its rrp tag.

 

He was bang on about the difference in TR vs UL.  The change is drastic. With the KT88 its pushes everything forward and singer right in your face almost.

I am still running the Willsenton tubes KT88.  Some suggest in tube amps to roll the power tubes first for most change but this amp seems to lean toward the pre tubes being swapped out first.

...that said, I am happy enough for now, I'll definately experiment but for the time being I am happy to leave good enough alone - before hitting the slippery slope!!

 

Great thread, I have to say it again!!

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4 hours ago, echorec said:

Ok guys, now the question is: Who's gonna change their caps?! ;)

Probably I wouldn't bother. Caps are like cables, bad caps and bad cables can deteriorate the sound but once at a standard level, any further better quality won't affect anything. R8 already seems to have good quality caps. I have changed on my previous amp Yaqin and it made a small difference but those stock caps were pretty ordinary.

 

This is my opinion being more a technical person than an audiophile 😉

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22 minutes ago, Atmaj said:

Probably I wouldn't bother. Caps are like cables, bad caps and bad cables can deteriorate the sound but once at a standard level, any further better quality won't affect anything. R8 already seems to have good quality caps. I have changed on my previous amp Yaqin and it made a small difference but those stock caps were pretty ordinary.

 

This is my opinion being more a technical person than an audiophile 😉

On paper maybe not, but in the real world they can have a profound improvement, but you need to know what to change to, changing from an ordinary cap to a slightly less ordinary cap is going to be more subtle or sideways move.

 

I embrace the technical side but keep an open ear ;) at the same time.

 

I don't have this amp, but do have a EL34 PP AB triode strapped amp, original coupling caps were like Benic or similar, then I bypassed them with Mundorf silver and oil, big audible change and a nice one, then I replaced that combo with Duelund Alexandra Copper Foil and Oil caps, better again if you prefer a more natural sound over all like I do.

 

They also have to be able to fit and some of the better caps are larger, definitely so with copper foil types, you also need to, or at least it is advisable to install them taking into consideration the outer foil end, this is in fact a technical aspect as orientated the correct way will allow better shielding of RFI.

 

Anyway, cap rolling is something I do even though I also adhere to technical aspects for the larger part in this hobby.

 

Each to their own paths though.

 

Edit: oops, typo

Edited by muon*
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On 21/10/2020 at 1:23 PM, 08Boss302 said:

Hi All..

Upto about a dozen hours now and all is good.

I am very happy with lows, I am finding the mids/highs  a bit forward and even maybe brittle, maybe even distored is a good word but its not true distortion. More so a sound presentation that is not my preference.  

Further burn in might settle this down but reading around it could also be the KT88 doing what they're designed to do.  Maybe they're not as forgiving with hard rock and metal as I was aiming for.  That small and very fixable thing aside  I have no humming or any other noise to raise any unwanted suspicions.   Its great. 

I have read around online with regard to tubes  to allow about 40hrs of burn in but am wondering if the KT88 will settle to the sound signature I like or if I need/should consider rolling these out sooner than my initial plan?

To provide clarity I am after a fat "laid back" sound.  Lows I like to have some kick,  mids dont need to be overly pronounced but a flat mid quite ok.. With highs, a sweeter sound, nothing overly exaggerated or glassy, even slightly rolled off is better than bright!!!  I am new to this rolling caper and also have some confusion about rolling the pre tubes or the power tubes first and which is going to have influence.

 

Based on reading through this thread and the rolling already done I am not sure the KT77 or 6550 are quite what I am after but also happy to advised otherwise.

I am thinking maybe the Tung Sol EL34B will be good. Most suggest its mids are clean and full, plenty of bass and slightly softer but well detailed top end all without being a forwardly accentuated presentation. 

For the 6SN7 I am thinking the Tung Sol GTB or the EHGold Pin both seem to be well regarded - not sure of any distinct SQ signature being vastly different.

For the 6SL7 I am thinking the Tung Sol or the Sovtek, again, pretty well regarded and not much to suggest much difference. 

 

Whilst I wont be pulling the trigger on any of the above this week or so I am happy to get some opinion on the above options.  I can keep playing music with all the stock tubes and if still itching for change I can make some purchases.

 

Cheers.

 

Hi Boss,

 not into speed/thrash type, but classic rock (inc Motorhead) rock/pop. prog, through to classical.

Allowing for the fact different ears, speakers, amps and brands of equipment/tubes produces a different sound, my thought would be this.

  Get some decent NoS tubes, doesn't have to be the 'holy grail' gear, but what would be 'average production'  back then, will still outperform 90%+ of modern tubes. (6SN7 & 6SL7). These will make the biggest difference to the sound. 6SN7's can tend to be microphonic, so you may need to look at isolation of the amp (pads/rubber) under the feet. KT77's will basically give you a KT88 type sound, 6CA7 could be a possible option in the EL34 type end of the tube family. I am running the Sovtek 6550WE at present, they are not a bad tube overall. Best advice for outputs is google search 'best sounding KT88' and you'll get a lot of info from forums, and sellers like the tubestore often have purchaser reviews. That'll give you an idea of the possible sonic signature you can expect.

 Some dislike Chinese tubes, some dislike the 'new sensor corp' tubes because they are now trading on the 'name' of some of the best tubes made, but they are NOTHING like the original. So maybe the standard EH tubes? Some I know in other forums are impressed with the Psvane KT88-2, others like  the Shuguang treasures, many say the 'new' Gold Lion (new sensor corp) are the best. At the end of the day, it's always a bit of a lottery as to what tube YOU prefer.

 

 

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