How can I run out of gain?

[kelossus]

At my budget of around 6k I am sure there are amps up to task. The hard thing is finding them on the 2nd hand market.

 

Pretty sure we have ruled out and impedance mismatch so the Pass Labs just isn't up to the task.

 

I am obviously an impulsive buyer and hearing the BHK with the Krell sent me down a regrettable rabbit hole. ....While a sensible precaution, trying before you buy is seldom an option with 2nd hand purchases. Most are interstate and you have to be quick. I should have waited until I had the Pass Labs and the Krell and made my selection based on simultaneous listening. I just jumped the gun given that I had owned both amps at the same time but with drastically different speakers.

Edited March 28, 2021 by kelossus

[wooferocau]

6 hours ago, metal beat said:

To be frank, I think you made a mistake with the X250.5.  I listened to the x350.5 at home a few years back. Bass was flabby, and lacked control. 

 

 

  

Agreed........ I tried several Pass Labs with the Sovereigns....  They lacked power and control always sound restrained and flabby.

 

The Manley 250 Neo,s with KT77,s  sounded wonderful with the Sovereigns.. as did my Krell KSA 250 and KMA 160 mono,s..

 

My last Amp ( ands still current)  i used on the Sovereigns, was the Esoteric  S1 Grandioso.. It defies its modest 145watt @ 8ohms !!

 

 

 

[wooferocau]

Many Many moons ago....

 

 

Edited March 28, 2021 by wooferocau

[xlr8or]

I've seen a Convergent Audio Technology JL2 Signature Mk II stereo power amp come up a few times in the SNA classifieds. Although double your budget that's also another tube-based option to consider.

 

 

Edited March 28, 2021 by xlr8or

[wooferocau]

On that note ......DONT let anyone tell you "TUBES" cant/wont power the Sovereigns  adequately !!

 

I rate the  Manley 250,s as on of the best amp/s i have ever used.   

 

Also...as seen in the pics, the Manley "Snappers" with 4 each of KT77,s  did a superb job of powering the Sovereigns....actually better than the Pass Labs X250.5 !!  

Edited March 28, 2021 by wooferocau

[tripitaka]

7 minutes ago, wooferocau said:

On that note ......DONT let anyone tell you "TUBES" cant/wont power the Sovereigns  adequately !!

 

That's a pretty comprehensive statement, without any regard to room size or listening level preferences.  The OP's original amp, Krell FBI, produced a lazy 1200W/ch.

 

I know 'watts arent watts', but I have a large listening room and if some kind person wants to bring some tube amps over to impress me then in return I will provide some very decent wines

 

[xlr8or]

13 minutes ago, tripitaka said:

I know 'watts arent watts', but I have a large listening room and if some kind person wants to bring some tube amps over to impress me then in return I will provide some very decent wines

 

 

Well bottles ain't bottles either. Who would want to swap some old sexy Hammersmith UK vintage Genalex Gold Lion KT77's with a decent red when the only thing they would have in common would be red plating.

[audiohifiaudio]

43 minutes ago, xlr8or said:

I've seen a Convergent Audio Technology JL2 Signature Mk II stereo power amp come up a few times in the SNA classifieds. Although double your budget that's also another tube-based option to consider.

 

 

Parasound jc5 one of the best amps I've ever owned for power and sound.

[tripitaka]

2 minutes ago, xlr8or said:

 

Well bottles ain't bottles either. Who would want to swap some old sexy Hammersmith UK vintage Genalex Gold Lion KT77's with a decent red when the only thing they would have in common would be red plating.

 

Well said 'kind person' would take their amps home, after drinking my wine, was that not clear?

 

[xlr8or]

2 minutes ago, tripitaka said:

 

Well said 'kind person' would take their amps home, after drinking my wine, was that not clear?

 

 

Thermionically and vacuum sealed clear.

[Telecine]

One observation, the input sensitivity of the BHK preamp is listed as:

 

Sensitivity

Unbalanced 1.3V/33KΩ
Balanced 1.3V/66KΩ

 

That is going to take a bit of driving with a phono stage and a SUT.

Edited March 28, 2021 by Telecine

[Martykt]

1 hour ago, wooferocau said:

Agreed........ I tried several Pass Labs with the Sovereigns....  They lacked power and control always sound restrained and flabby.

 

The Manley 250 Neo,s with KT77,s  sounded wonderful with the Sovereigns.. as did my Krell KSA 250 and KMA 160 mono,s..

 

My last Amp ( ands still current)  i used on the Sovereigns, was the Esoteric  S1 Grandioso.. It defies its modest 145watt @ 8ohms !!

 

 

 

People quite often put too much credence on the spec sheet.

I've heard a measly 25 watt class a amp happily drive a pair of speakers that a 100 watt amp couldn't manage and a 500 watt class d amp that really couldn't do much at all.

 

[kelossus]

17 minutes ago, Telecine said:

One observation, the input sensitivity of the BHK preamp is listed as:

 

Sensitivity

Unbalanced 1.3V/33KΩ
Balanced 1.3V/66KΩ

 

That is going to take a bit of driving with a phono stage a SUT.

Oddly enough the SUT has more audible gain than the Directstream DAC in my system.

 

 

In regards to valves, I definitely wouldn't rule them out even though I am extremely skeptical as to how they would perform. 200-300 watts of valve amplification ain't coming cheap.

[Ooogh]

5 hours ago, kelossus said:

Yep that certainly makes sense.

 

If anyone in Brisbane thinks they have an amp up to the task I am willing to give it a go. I wouldn't want to waste a dealers time when I have no intent to purchase.

 

I know someone with an ME1500 I could give a crack but they don't play well with tube pre's.

 

 

Absolutely try the big ME, it is a known working solution with Duntech’s.  However, unless your friend has a matching ME preamp to couple it to then chances are you will have an  unpleasant time. Very annoying but ME amps simply demand the matching preamp to show what they are capable of.

 

Another alternative is a monster Bryston 14B. An arc welder and warmer sounding than the ME, also much more preamp friendly. The later models are better than earlier ones, SST2 would fit the brief and budget perfectly if you can find one.

 

@christosd can expand with his experiences running big Duntech’s.

[Guest Eggcup the Dafter]

54 minutes ago, Martykt said:

People quite often put too much credence on the spec sheet.

I've heard a measly 25 watt class a amp happily drive a pair of speakers that a 100 watt amp couldn't manage and a 500 watt class d amp that really couldn't do much at all.

 

All very true, and independent review measurements, or understanding the purpose or limits of a particular design can often show why. 
My Marantz amp would possibly not drive the Sovereigns well, yet the new and less powerful (into 8 Ohms) Model 30 at a third of the price should.
 

That doesn’t mean that the PM-10 doesn’t do a better job with my own speakers, or with 99% of all loudspeakers. 
 

The X250 has a specific design goal and driving the Sovereigns isn’t it. So?

[kelossus]

20 minutes ago, Eggcup the Dafter said:

All very true, and independent review measurements, or understanding the purpose or limits of a particular design can often show why. 
My Marantz amp would possibly not drive the Sovereigns well, yet the new and less powerful (into 8 Ohms) Model 30 at a third of the price should.
 

That doesn’t mean that the PM-10 doesn’t do a better job with my own speakers, or with 99% of all loudspeakers. 
 

The X250 has a specific design goal and driving the Sovereigns isn’t it. So?

Yeah I agree. You need the right for the right amplification.

 

I do think it's hard for people to understand given the praise and following Pass Labs gear has that a big amp like the 250.5 can't drive a speaker. I wouldn't of fully believed it till I heard it.

[muon*]

A pair of Bob Carvers Black Beauty monos would do the trick, 290 watts into 2 ohms

[wooferocau]

9 hours ago, tripitaka said:

 

That's a pretty comprehensive statement, without any regard to room size or listening level preferences.  The OP's original amp, Krell FBI, produced a lazy 1200W/ch.

 

I know 'watts arent watts', but I have a large listening room and if some kind person wants to bring some tube amps over to impress me then in return I will provide some very decent wines

 

I am a long term Krell lover and Owner ....BUT i will tell you one of the most disappointing amps i tried with  Sovereigns  was the FB600 !   All the power in the world , but little else in its favour!

[andyr]

You said you like buying 2nd hand @kelossus ... but see if you can audition a Magtech.  I am sure that with 500w into 8 ohms, 900w into 4 ohms and stable into 2 ohms - it will be able to do justice with your Duntechs.

 

Andy

 

[Guest DrSK]

13 hours ago, Eggcup the Dafter said:

20 amps maximum output current if I remember rightly,

 

13 hours ago, Eggcup the Dafter said:

 

20A max is nothing much at all. 

 

 

[Jakeyb77_Redux]

WELL 
 

 

Edited March 30, 2021 by Jack Goff

[stereo coffee]

21 hours ago, kelossus said:

First off I am serial gear changer. I never seem to be happy with what I have and am always chasing something that seems unattainable.

 

My current issue started with the introduction of a BHK preamp and the subsequent sale of my Krell FBI. The FBI is one hell of an integrated and the preamp section had fended off many contenders. That was until the BHK was introduced. Contrary to some of the older Krell's the FPB series is actually quite warm and rich but still a tight and powerful sound. With the BHK installed I could not believe how much more bass impact and depth I was getting. The downside, it brought the soundstage a little further forward and it could get a little fatiguing, something I had never had with my Duntech Sovereigns in the past.

 

I decided to sell the Krell FBI as I now had a preamp that seemed to be next level. The FBI went and a Pass Labs X250.5 landed as a replacement. At this point I was playing strictly vinyl but hadn't been listening as my turntable was off getting warranty repairs. I bought another turntable in the interim so outside of the speakers a lot components had changed. I had had the X250.5 in the past but with very different speakers. At the time I did not think the Pass Labs would be a slouch in the bass and dynamics department compared to the Krell and I did prefer the mid-range of the X250.5 over the Krell last time I heard it albeit with different speakers.

 

Upon firing everything up I was extremely disappointed. The bass was no longer impactful and the sound was soft and mushy. Given the amount of component changes I had no idea what to blame but seemed to pick on the turntable. Still I have no idea why the sound is the way it is but I am starting to consider possible impedance mismatch????

 

Last week I scored a Directstream dac, a component I was familiar with having lived with one in my system for a months in the past. I got it working last week and had a list of tracks in my mind to revisit. I have not been listening to hi-fi as of late, I chop and change so much gear and get in these ruts where nothing sounds good anymore. Then the obvious critiques come to mind, "Why did I sell this", "I should have left it as is". Curiosity gets the better of me and I have to try other gear.

 

Back to the root of my main issue. The Pass Labs has an input impedance of 20k and the BHK preamp is 200 ohms output impedance. Compared to the Krell which had input impedance 100k the difference is substantial but whether it would actually make an audible difference, I don't know. With the Directstream, which has a little lower output than standard, I can turn the BHK up to 100 on certain tracks. I do listen loud but even at 100 I could take it further. This was not the case with the Krell, it seemed limitless. On vinyl I can crank the BHK to mid 80's but have a fair whack of gain due to my SUT.

 

Is the lack of gain, bass dynamics and softer sounded a possible impedance mismatch? Could it be system synergy? Or is the Pass Labs a whimp compared to the Krell? Is it a combination of  things?

 

My system consists of:

 

Duntech Sovereigns

Pass Labs X250.5

BHK Preamp

Directstream Dac

Icon Audio PS3 Signature Phono

Sota Nova SME IV w/ Windfeld TI

 

I bought the Coincident Statement preamp last week but haven't plugged it in yet. I wanted to hear the Directstream in my current system before confusing me further.

 

 

Its simply a matter of coming to terms with consumer line level, which requires, if you require no reactance in between, ... for power amps to be of similar sensitivity, as exampled. 

 

If you happen to some how be convinced that adding reactance in between your source and power amp, is desirable, you need to solve firstly that amplification, to achieve different sensitivity,  to then match to  a higher sensitivity, always adds undesirable change away from the capability of the source. That change is complex but is mainly reactance, which differs to resistance in profound ways,  which alters music reproduction.  https://en.wikipedia.org/wiki/Electrical_reactance  

 

 

 

 

 

[Guest DrSK]

1 hour ago, Jack Goff said:

Amps not watts...... 

 

ME or Krell. 
 

 

 

Electrocompaniet too (mine claims over 100A)

[Ittaku]

3 hours ago, DrSK said:

20A max is nothing much at all.

20A would be a busload for a valve amp, but most quite affordable larger class D amps easily trump this value.

[Guest DrSK]

23 minutes ago, Ittaku said:

20A would be a busload for a valve amp, but most quite affordable larger class D amps easily trump this value.

My Electrocompaniet and Metaxas solid states (Class A before switching to A/B) are around the 100A mark. 

Edited March 29, 2021 by DrSK