Fine tuning the sound, quality caps, and pot, where and what to buy?

[aussievintage]

 

With new Psvane 12AX7s on the way for the phono preamp,  I have decided that my next spend will be on my line preamp  and will be output coupling caps and a good potentiometer for the volume control.

 

So, being on the output of a 12AU7 cathode follower at up to at least 140 volts, a 100V cap isn't good enough.  I'd like 250 to 300 at least.   I am looking at about 2 uF in size.  I know many people spend time upgrading coupling caps, my only experience is upgrading Jaycar caps to Orange drops,  so I thought I'd ask what is good quality, and where to buy them from.  Anyone in Australia selling them?  

 

Same for the volume control pot. Dual gang, at least 100K.  I hear lots of talk about ALPs.   Same questions, I guess, what's the best alternatives?  Where to buy?

 

 

 

 

[Ittaku]

How much do you want to spend? The sky's the limit for caps, just like everything else. ALPs is the way to go for the pots at least, unless you want to move to a stepped attenuator, then the sky's the limit...

[Ittaku]

For caps, if you wanted to go straight to the top this would be my recommendation, and buy it from here, $80USD a piece:

https://www.tme.com/au/en/details/kpcu01-2u_600/audio-polypropylene-capacitors/miflex/kpcu01h520j/

if you wanted something much more affordable, these would be my recommendation, at just $2.70USD a piece:

https://www.tme.com/au/en/details/mkp10-2.2u_600/audio-polypropylene-capacitors/miflex/mkp10h522g-c/

 

I use both these types in my speakers' crossovers.

Edited October 12, 2019 by Ittaku

[aussievintage]

4 minutes ago, Ittaku said:

How much do you want to spend? The sky's the limit for caps, just like everything else. ALPs is the way to go for the pots at least, unless you want to move to a stepped attenuator, then the sky's the limit...

I know some caps cost hundreds.   Is there a knee in the price curve?  A point where, say $50 will get you most of the way there?

 

Ah, you mention a stepped attentuator.  Another good idea if I can fit it in.  Yes, put that possibility on the list too. thanks.

[Ittaku]

1 minute ago, aussievintage said:

I know some caps cost hundreds.   Is there a knee in the price curve?  A point where, say $50 will get you most of the way there?

Yeah see my followup post on caps.

[aussievintage]

1 minute ago, Ittaku said:

if you wanted something much more affordable, these would be my recommendation, at just $2.70USD a piece:

https://www.tme.com/au/en/details/mkp10-2.2u_600/audio-polypropylene-capacitors/miflex/mkp10h522g-c/

 

Our posts crossed up.  So I can get "good" for less than expected as you suggest in this link?  Great!

 

2 minutes ago, Ittaku said:

I use both these types in my speakers' crossovers.

A coupling cap is a different application, but I guess they mostly likely will be good at both.

[Ittaku]

6 minutes ago, aussievintage said:

Our posts crossed up.  So I can get "good" for less than expected as you suggest in this link?  Great!

 

A coupling cap is a different application, but I guess they mostly likely will be good at both.

I think the 'affordable' ones from miflex are exceptional - they're just a capacitor manufacturer, nothing else. Those affordable ones are low ESR, non-inductive, resin bound,  and tight tolerance oil-immersed metallised polypropylene. The type of cap makes the biggest difference, and then it's the quality differences between different manufacturers.

 

There's enough crossover in the requirements for caps in all uses, just make sure of the heat compatibility in your case.

 

If you want to shop around and see what's available, this is the best but dizzying selection online for audio caps.

https://www.hificollective.co.uk/components/capacitors.html

 

Edited October 12, 2019 by Ittaku

[Ittaku]

There's also this infamous "ranking" site for coupling caps. Take it with a grain of salt, most of his ratings are just proportional to cost.

 

http://www.humblehomemadehifi.com/Cap.html

[aussievintage]

18 minutes ago, Ittaku said:

I think the 'affordable' ones from miflex are exceptional - they're just a capacitor manufacturer, nothing else. Those affordable ones are low ESR, non-inductive, resin bound,  and tight tolerance oil-immersed metallised polypropylene. The type of cap makes the biggest difference, and then it's the quality differences between different manufacturers.

 

There's enough crossover in the requirements for caps in all uses, just make sure of the heat compatibility in your case.

 

If you want to shop around and see what's available, this is the best but dizzying selection online for audio caps.

https://www.hificollective.co.uk/components/capacitors.html

 

 

Fair enough.  Thanks for the links

 

[Guest Muon N']

I have KPCU01 bypassing Andyn Copper caps on the output of my CD Player, they work well as a combo.

Any of the premium copper caps are going to be big, using thicker foils/dielectrics for the most part.

 

My experiences have mostly aligned with those in the humblehomemade cap tests, not all, but most and without priming and some of his rankings go against the higher priced caps being better than a lower priced one, so I don't see any biases in favor of the higher pricing, It's just a fact that the more premium caps often will cost more due to materials used and construction.

AS always, the outcome and favour of any passive parts will be subjective and come down to the personal preferences of the listener, and how a sound signature works with the system as a whole....So the YMMV is applicable.

[Guest Muon N']

I prefer partsconnxion in Canada over hificollective in the UK, for pricing at least.

Edit: both stores offer very good service, and you are pretty much guaranteed the real thing that you have ordered.

Edited October 12, 2019 by Muon N'

[Guest Muon N']

I think there are better wipper pots than the Blue Alps, but that's only my opinion, I use a Tocos Cosmos carbon pot in my amp, way better sounding than the Blue Alps, and edging out others like the Noble ect'.

 

Two reviews that are linked on hificollective.

https://hfc-fs.s3-eu-west-1.amazonaws.com/s3fs-public/cosmos_review_neville2.pdf

https://hfc-fs.s3-eu-west-1.amazonaws.com/s3fs-public/albarry_music_cosmos_review.pdf

 

Unfortunately It's a bit hit an miss in respect to channel balance with the stereo ones, but the one I have is OK in this regard. Maybe they can check this if requested when purchasing.

 

Earle favoured these in his amps in the past.

 

Or maybe buy a few as they are cheap, I got mine off an ebay seller for about $8 each (RV24RG). I think there is a RV30 variant that is said to be even better, but I can't recall the details.

 

Edit: OK, they seem to cost a little more these days, with our weak dollar.

Edited October 12, 2019 by Muon N'

[Guest Muon N']

Did you say 100k?

 

This is the seller I got mine from, maybe ask if he can check the channel balance of any you purchase.

https://www.ebay.com/itm/1pc-COSMOS-TOCOS-Potentiometer-RV24YG-20S-15A104-x2-A100kΩx2-A100K-24mm-Japan/131982915086?hash=item1ebacb760e:g:0eUAAOSwI-BWF94T

[aussievintage]

11 minutes ago, Muon N' said:

Or maybe buy a few as they are cheap, I got mine off an ebay seller for about $8 each (RV24RG). I think there is a RV30 variant that is said to be even better, but I can't recall the details.

That's what I have decided to do - buy a few and try them.  I just ordered a blue ALPs pot for $15 - paid a bit more because it is in Australia, so quicker delivery.     I also always worry about fake parts, hope this one isn't.

 

That Cosmos is certainly built the old way they used to make 'em :).     It will be interesting to compare.  I am not sure about reviews hearing better highs and more or less bass etc.  I mostly want channel balance and reliability.  Also, the feel of the pot matters to me. I like to feel some resistance to turning it, but it has to glide smoothly as well.  On that front, the Jaycar cheapy in there right now isn't too bad surprisingly.

[aussievintage]

4 minutes ago, Muon N' said:

Did you say 100k?

 

This is the seller I got mine from, maybe ask if he can check the channel balance of any you purchase.

https://www.ebay.com/itm/1pc-COSMOS-TOCOS-Potentiometer-RV24YG-20S-15A104-x2-A100kΩx2-A100K-24mm-Japan/131982915086?hash=item1ebacb760e:g:0eUAAOSwI-BWF94T

Might need to get one of them too. 

[Guest Muon N']

They feel smooth as you rotate them, but of course the channel balance means you want to try and get one that is matched well in this regard. Hificollective stopped stocking the stereo ones as the manufacturer, in Japan I believe, couldn't guarantee them all closely matched, or that's what they have on their web site anyway.

 

Mines a Linear one, and I may get myself a Log' one to replace it with.

Edited October 12, 2019 by Muon N'

[aussievintage]

Just now, Muon N' said:

They feel smooth as you rotate them, but of course the channel balance means you want to try and get one that is matched well in this regard. Hificollective stopped stocking the stereo ones as the manufacturer, in Japan I believe, couldn't guarantee them all closely matched, or that's what they have on their web site anyway.

 

Nines a Linear one, and I may get myself a Log' one to replace it with.

I always use log.  

[Guest Muon N']

1 minute ago, aussievintage said:

I always use log.  

At the time I could only see a Linear on available in 50k, so that's what I ended up with.

Meh, Linear works for me in my amp, so I may just leave it as is.

 

Most people do prefer a Logarithmic type

[Guest Muon N']

I wonder if channel balance is more often better with one type or the other, in regards to the Cosmos and Linear and Log'.

 

Eh, I may be over thinking it now

[Gryffles]

If you want a good pot then look at TKD. Cost a bit but sound good.

[aussievintage]

2 hours ago, Gryffles said:

If you want a good pot then look at TKD. Cost a bit but sound good.

I saw them mentioned in a comparison article, yes.

[aussievintage]

 

More preamp surgery surgery today. 

 

Added an ALPS pot and cheaper polyprop caps (for now).  I replaced the hobby grade polyester caps because I keep reading that they are the worst type.  

 

Tweaks on the preamp so far ...

1. removed tone controls and converted last gain stage 12AU7 to cathode follower as extra gain not required. Gives preamp the ability to drive lower impedance power amps
2. Chose 12AZ7 as a cathode follower valve for lowest output impedance.
3. Psvane 12AX7 T MkII valves chosen for phono stages
4. Tried many 12AU7 valves in gain stage before the cathode follower.  Settled on smooth plate AWV 12AU7 or 12BH7A (both sound very nice)
5. Rubber damper rings put on 12AX7 phono stage valves
6. ALPS pot fitted for main volume control
7. Polypropylene caps substituted for Polyester on output.  Still deciding which audiophile caps I might try.

 

Still to do (maybe).  Upgrade caps in phono stage eq network and coupling.  Most other caps in the circuit are sprague orange drops, so maybe they're OK.

 

[aussievintage]

Oh, and those cheap polyprop caps have produced a quite noticeable improvement.  OK, I did put them in at the same time as the ALPS pot, but the pot was more a reliability tweak, and I am attributing the SQ improvement to the caps.

 

So, the caps are from a Hong Kong company.  Jaycar happen to be selling them as crossover caps.  Jaycar's web site picture shows generic unbranded caps, so maybe they have substituted these since then.   The 2.2uF were about $6.

 

 

[Guest Muon N']

They will sound better in ways (transparency ect'), but wait till you can compare them to something really good

Edited October 21, 2019 by Muon N'

[Monkeyboi]

IME as far as capacitors and resistors are concerned you really need to consider the design and what other components are in the circuit.  There is an arguable case for rapidly diminishing returns on your $ investment.  IMHO it's more about choosing the right type of capacitor or resistor for the application rather than paying hundreds of dollars on esoteric (perhaps even "snake oil") audiophile branded components.

 

Yes, better quality components from major established manufacturers are more like to provide consistent and reliable performance than the buy of the day el cheapo WunHungLo brand from the Shenzhen markets.  At the other end of the scale some DIYers are paying ridiculous amounts for "audiophile" components of questionable merit. 

 

Now I can hear the assembled masses already screaming "Moderators where are you?  Remove the post.  Words of a heathen." 

 

Well folks I am constantly amused by the lack of technical information provided by some of these purveyors and manufacturers of audiophile components.  Hardly if any information about the reliability (expected operational life), warranties (expressed or implied), surge voltage ratings, ripple current ratings, ESR, tolerance ratings, operating temperature range, dissipation factor, leakage current, etc, etc.  Instead I see lots of lovely subjective information of how the compressed paper outer layer - "strengthens the damping properties of the design helping music flow effortlessly."; "... nuances with such detail that  you can hear a snowflake land...." ; "musical ", "warm tone" and almost any other subjective claim that is likely to be just as difficult to prove as it would be to disprove.  

 

Now I recognise that some people can actually hear the difference between a $5 metalised polypropylene capacitor and a $250 paper in oil capacitor.  Maybe they have super hearing or could it be that they replaced all the capacitors in their speaker crossover networks and didn't notice any night vs day improvement but truthfully they aren't going to admit that they didn't really get good value for money with the capacitors costing 50 times more, are they????

 

Anyhow, the bottom line is just use quality parts with a verifiable lineage from reputable suppliers / manufacturers and most importantly the right type of part for its intended application.  I usually avoid Chinese based eBay garbage.  The eBay market is full of fakes and audiophoolery.  Some counterfeit parts looking more and more like the genuine article every week, but alas fail the performance measurement tests when compared to the genuine component.

 

Cheers,

Alan R.