Any tube amp guru help identify components in circuit.

[Happy]

On 19/09/2017 at 8:22 PM, Noum said:

*sigh*

 

I respect you ZB and your knowledge but this Chinese amp bashing is like a broken record.

 

Yeah, I disagree with a fixed statement like that, I do agree the OPT's are very important to the sound possibly the most single important thing, but to disregard everything else that influences the sound is something I do not agree with.

 

But I'm small fry so I'll leave it there

Edit:  forgot to mention that the OP has an amp and is not asking for recommendations, so....I don't understand the post. I also think Earle's amps are nice amps with fine transformers, and good value, but when It's often accompanied with the putting down of other amps, I don't see it as needed, Earle's amps can sell themselves, and Earle offers 5 star service.

 

Talking down Earle's amps publicly is a bit of taboo here but I for one disagree with the statement that Chinese tube amps necessarily sound worse. In the world of PMs and private convos there are polarising views.

[MattyW]

I've not seen anyone talk down Earles gear at all... So far just anti Chinese amp sentiment which I think a bit uncalled for.... I hope to someday own either an amp by Earle or Paul at Falls Audio some day. For now I'm extremely happy with my two Chinese Oldchen amps which are very very nice little starter amps. Certainly better than what Yaqin churn out

Edited September 21, 2017 by MattyW
typo

[skies2clear]

6 hours ago, kelossus said:

 

Are the signal coupling capacitors the most influential to overall sound of the amp? Should I get the best caps I can afford for these?

 

The other film caps on the small tubes are they less important? The 22uf's must have had an impact on the sound if Lenehan only decided to change the 8 signal coupling capacitors and the 4 electros. I believe now he replaces all the white caps as well the 4 electros.

No doubt the signal coupling caps are very influential to overall sound. I am not all that familiar with the performance of this amp to be honest, but assuming its basically a good performer then I don't see any reason why spending for much better caps wouldn't be worth it.

 

 I would think the other 4 coupling film caps are just as important, but looks like the other 8 were easier to replace as far as access goes (but easily doable nevertheless).

 

The 4 electros: look at their voltage rating at 450V....this is usually a dead giveaway they are not cathode bypass caps. Cathode bypass caps would normally only be 100V rated max. I suppose it is possible they used 450V, but it is unusual! If you could post a higher resolution image of that area for a double check? (I'm not 100% sure without a better look). Jensens are fine btw! I'm not overly blown away by their paper and oil stuff for signal coupling (had some reliability issues), but their Electros are OK.

 

The Jupiter range of caps is pretty good. So are Mundorfs and others, but it all comes down to how one feels things need to be voiced and this will be based on the rest of the system balance and listeners preferences....tough one to answer!

Edited September 21, 2017 by skies2clear
Spelling error

[trobbins]

Definitely try the placebo affect - it is statistically proven to make an improvement.  Unsolder the caps you have noted, and swap those in the left channel for those in the right channel, and then solder them back.  Very low risk you will damage the amp, and very likely you notice an improvement, especially if you turn the volume up a titch more than normal.  You will also get that glow of satisfaction that you've done the changes yourself, and if you ever locate another same amplifier then you'll be able to prove the affect with a double blind test.

 

Edited September 25, 2017 by trobbins

[VanArn]

Apart from the placebo influence effecting perceived results,  replacing the coupling capacitors in just one output amplifier block and not the pre-amp front end, will allow a comparison to be made between the different capacitor brands. If a mono  audio signal can be supplied and possibly just the one speaker switched between the left and right amplifiers, any sonic difference due to the capacitors  should be discernible.

[mwhouston]

On 19 September 2017 at 4:27 PM, VanArn said:

 You need to have a circuit schematic or a knowledge of valve circuits to help indentify the exact  components  and whether they are critical to obtaining the best performance. Anode to grid capacitors require very low levels of leakage and  dielectric absorption and polypropylene capacitors are already the better performers, especially  of film and foil construction and of  the highest available voltage rating. The crucial  component in designing a valve amplifier is the output transformer , this is followed by the actual cct. design and  the  layout.

Schematic would help but descriptions like "output pin" really is too ambiguous. 

[mwhouston]

On another note the caps look quality and Primaluna is a respected brand. I'd be leaving it as is. You could spend a lot of money and time changing passive so for no improvement. The worse case is you snap off a tag or short something out in your quest to cause real damage. 

 

Leave it as is. Or build your own tuber with parts you would like to use. I do.

[Guest Muon N']

I can see an improvement in swapping to Jensens and Jupiters, if that is the sound you are after there's nothing wrong with that.

 

If someone sees no benefit, they don't need or have to change, if someone does It's their call/choice the way I view it.

Edited September 26, 2017 by Muon N'

[kelossus]

47 minutes ago, mwhouston said:

On another note the caps look quality and Primaluna is a respected brand. I'd be leaving it as is. You could spend a lot of money and time changing passive so for no improvement. The worse case is you snap off a tag or short something out in your quest to cause real damage. 

 

Leave it as is. Or build your own tuber with parts you would like to use. I do.

What capacitors have you used/tried in your builds? I only ask as some do not think exotic brands like Mundorf/Jupiter/Duelund have any sonic benefits over a standard cap.

 

I was quite annoyed with the Primaluna as in promo videos of this amp they mention using Mundorf M-Cap Evo Oil's in critical locations. There is not one Mundorf inside an having no name brands like Du-Roch worry me.

Edited September 26, 2017 by kelossus

[Happy]

3 minutes ago, kelossus said:

There is not one Mundorf inside an having no name brands like Du-Roch worry me.

it is a bit of feat not to have your brand name caught by the almighty Google searches nowadays. 

[kelossus]

Just now, Happy said:

it is a bit of feat not to have your brand name caught by the almighty Google searches nowadays. 

Agreed, they could have at least rebranded them as Primaluna, I reckon they would be rubbish compared to even an reasonable priced capacitor like Jantzen Superior.

 

My speakers are pretty revealing and are a tad treble heavy. At the moment with the KT150's the Primaluna grates my ears.

[Happy]

3 minutes ago, kelossus said:

My speakers are pretty revealing and are a tad treble heavy. At the moment with the KT150's the Primaluna grates my ears.

hmm wouldn't that indicate the amp is doing its job fine?

[MattyW]

Mmmm, sounds like you need to EQ the system. I have a MiniDSP 2x4HD HD I never ended up using if you want it?

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[kelossus]

1 hour ago, Happy said:

hmm wouldn't that indicate the amp is doing its job fine?

 

I probably spoke too soon but I only found the speakers treble heavy when I changed amps. Either my speakers were that way before and my previous amp paired better or its the Primaluna, I am probably wrong to make the assumption that because they are horns they can favour the treble but that is why I said it.

 

The speakers do not have the full bottom octave of my previous speakers, compound that with using a Tube Amp which does not have the control over the bass in sub 50hz region like the SS amp before it,  all this has dramatically changed the presentation. I added a sub last weekend but have to rearrange the room to declutter it.

 

Also I am still dialling in my TT, the Well Tempered Versalex is an absolute pain in the arse to setup IMO. Ever since I changed Carts i am battling Inner Groove Distortion, as you know the Well Tempered have no overhang adjustment or antiskating adjustment. I am still playing with the tonearm damping and it may still be a tad under damped. Unsure if this could cause IGD but  its starting to get pretty annoying.

 

[Gryffles]

2 hours ago, kelossus said:

Agreed, they could have at least rebranded them as Primaluna, I reckon they would be rubbish compared to even an reasonable priced capacitor like Jantzen Superior.

 

My speakers are pretty revealing and are a tad treble heavy. At the moment with the KT150's the Primaluna grates my ears.

Be wise in your choice of cap if you have treble problems. I'd suggest PIO of some description.

 

Mundorf and Jantzen would not be suitable IMO

[kelossus]

Just now, Gryffles said:

Be wise in your choice of cap if you have treble problems. I'd suggest PIO of some description.

 

Mundorf and Jantzen would not be suitable IMO

 

Jupiters?

[Gryffles]

7 minutes ago, kelossus said:

 

Jupiters?

Thats what I use in my 2A3 amp and they are very nice and have a sweet, airy top end. Best PIO I tried was Ampohm but they are slower overall like all PIO

[kelossus]

1 hour ago, MattyW said:

Mmmm, sounds like you need to EQ the system. I have a MiniDSP 2x4HD HD I never ended up using if you want it?

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Appreciate the offer but I have not had good experiences with DSP's in the past. Mostly due to my lack of knowledge and unwillingness to learn.

 

Thanks though mate.

[MattyW]

 

Appreciate the offer but I have not had good experiences with DSP's in the past. Mostly due to my lack of knowledge and unwillingness to learn.

 

Thanks though mate.

Lol. Yeah, I bought them though never tried them as I couldn't be bothered setting up so I've a similar issue there

 

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[kelossus]

19 minutes ago, Gryffles said:

Thats what I use in my 2A3 amp and they are very nice and have a sweet, airy top end. Best PIO I tried was Ampohm but they are slower overall like all PIO

 

I had the Jupiters in a DHT Preamp previously so am inclined to use them again.

[Happy]

Lol. Yeah, I bought them though never tried them as I couldn't be bothered setting up so I've a similar issue there 
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I did express my concern in this regard!


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[Happy]

It might as well be the Prima is a more revealing amp than your previous one? Dunno if changing caps should have the effect of altering the frequency balance of an amp. Hopefully dialling in the sub might ameliorate the issue


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[kelossus]

I am hoping that a change to KT77s or EL34 as well as the Capactior upgrade will remedy things.  Why would changing caps not have an effect on the frequency balance, the same way a tube rolling can.

[MattyW]

 

I did express my concern in this regard! [emoji3]

 

 

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Yes, you did. Noum also.... I just can't be bothered with technology when I come home from work.... I like the opposite of high tech. No remotes except for the TV.... Though I kind of wish my DAC had one.  

 

 

 

Chris, I suspect EL34's would lessen the treble extension though unfortunately you might lose the lovely bass too. How is it sounding with digital content?

 

I find optimising for digital playback on the amp a good starting point, and tube roll in the phono stage and try cartridges until I'm happy with the analog. I've quite a few cartridges on hand here if you'd like to try any of them?

 

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[Guest Muon N']

Different caps can alter tonality and that balance, if it actually changes the frequency response I have no idea.

Changes need to be considered in the whole of the system balance. Copper/oil caps and EL34's should place an emphasis on the mids and add some weight to the presentation.

 

Thinking out loud here and subjectively.