ToolShed Amps thread, Transcendence / Iron-Coupled / Tanoshi

Thank you @Deleeh !

The Vcap ODAM (or CuTF, i dont remember exactly anymore) were originally going to go into the amp but the builder thought the silver jupiters to be better.

I would like to hear about the other caps you tried even if they didnt make your top 3. You mentiomed taking odams over deulands but id love to know what you heard to make that choice.

With you Feliks what were you trying to change? How would you describe it before vs after, and was something bothering you with the sound or more for experimentation?

Yes i am not looking forward to 100-200 hour burn in after each swap. For me its to ease the amp and spread out that single point that all the music seems to originate from, make it a stage not a single spot. I also NEED to de-emphasize that upper mid spot or else it starts aggravating my ears.

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Hello,
So the Odam was fitted into the Feliks Euforia back then because I’d previously installed the TFTF from Vcap on the 6SN7.
Ultimately, with the standard Mundorf capacitor fitted, I had a sharp and harsh treble peak that was simply awful.
I can’t say for certain whether it was down to the capacitor itself – perhaps it was simply faulty – or whether the materials used were poor.
The fact is, though, that it’s simply a cheap capacitor.
Once I had the Odams fitted, nothing was the same again – but in a good way.
The harshness was gone, as was the annoying peak; after the burn-in period, the Feliks Euforia simply sounded better – rounder, fuller, deeper – and, above all, the spatial imaging was more tangible.
The musical presentation had also simply become more rounded afterwards; tubes that I’d previously been less keen on became my favourites or simply sounded better.
Both the Odam and the CuTF never sound harsh at the top end; if they do, it’s always well-balanced and usually spot on.
Vocally, too, the midrange is richer, more tangible, a bit more in-your-face – but again, in a good way: never too much, never too little.
It’s always been worth the money, even if it’s a bit of a pain, and the burn-in too – but you have to say that once that’s over, you forget all about it after the first tones.

The non-Vcap option would be the Audionote Copper, which is roughly the same price or slightly cheaper than the Odam.
But it’s also a good cartridge: warm, full-bodied, superb bass and top end, with an intimate vocal range that leans more towards coherence – the treble is never grating.
Overall, very musical.
Sonically, it’s not far off the CuTF; the soundstage isn’t quite as expansive, and here and there the details are a touch less pronounced.
I like it, even though it perhaps leans slightly towards a British-style tuning.
If you have both and can switch between them via a switch on the amplifier, I’m glad to have both.
Because the Audionote tends to be very well suited to neutral headphones, whilst the Vcap CuTF and Odam are more suited to warmer headphones.
As the two Vcaps are more neutral than warm.

If you want my honest opinion on silver, I don’t think it has any place in valve amplifiers.
Neither silver-plated capacitors nor Audionote’s silver resistors.
They simply ruin the sound, especially in the upper frequencies.
Opinions are divided when it comes to cabling.
You can use it, but you don’t have to.
Generally speaking, a neutrally tuned valve amp with no silver components in the circuit is sufficient on its own, paired with neutrally tuned speakers or headphones.
Alternatively, you always have the option of using hybrid or silver cables for the speakers or headphones.
This helps to prevent the sound from becoming too warm or muddy.
I had the chance to listen to the Feliks Elise once, and in the end I preferred it to the Euforia because the internal wiring was different.
That’s why the Euforia always sounded a touch sterile and somewhat emotionless to me, due to its silver wiring.
I should have made more use of resistors back then.
That would have made the combination even better later on with the Vcap modification.

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My 2c is not a lot, you might want to go bigger than 0.22uf, I can’t remember off the top of my head what I used, I’ll look it up later and update. In effect the capacitor does form a filter with the input impedance of the following stage, but in practice that’s usually large, so even for smaller values, the cutoff frequencies are outside anything audible,

There is more of an effect if the output is capacitively coupled IME, interstage coupling never made a huge difference in my experiments, but I did always massively oversized them.

It is audible, but it’s unlikely to change the nature of of the amp.

I used a 1uF coupling cap in the hybrid amp, you won’t get away with that on a 300B, you should get away with anything between .22uF and .47uF, larger values move the frequency cutoff lower. But even .22uF should be in the single digit Hz for most designs. FWIW I ended using a smaller polyester film cap after testing various options.

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In my experience its been mixed. The two silver only cables ive put ears on really were not for me. Cables that were split or mostly copper with a few silver strands were much better. The all silver cables had a very similar feel to what ive heard in this amp but until i try i can only say that is a very, very shakey thing to base things on. The silver vitamin Qs have been used in many amps successfully.

I did .22uf to match what was in there. I expect as in most things audio it really will depend on the amps design and the chain. Forgive my ignorance here, but what would increasing the value of the cap likely change?

And to be clear, there is some brilliance to the amps sound. I made it sound all doom and gloom but it is more like some imbalances that dont agree with me.

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You can imagine the circuit ammounts to a high pass filter. it’s job is to remove DC, but because the input impedance into the power section isn’t infinity, it actually filters low frequencies as well.
The actual frequency cutoff depends a bit on the design on of the input to the power section, if there is a grid stopper resistor it’s probably in the 100K range, so your actual frequency cutoff for a .22uF capacitor would be about 7Hz and could be lower, for a larger .47uF capacitor it’s more like 3Hz.
The filter is a good thing because there are also phase shifts at both ends of the frequency spectrum, and if that cutoff get’s too low these can cause instability in the amp.
Generally .22uF is considered a good value for coupling on 300B amps, anythin in the >1uF range is likely to cause instability.

My guess is the larger value would probably sound ā€œbiggerā€.

But again I wouldn’t expect night and day, I could certainly hear the difference when I experimented, but it never really changed the overall ā€œnatureā€ of the amp.

FWIW I think the pre section is more likely to be giving you the imaging persentation you don’t like. C3G’s are just VERY linear, even triode strapped and even more so if it’s not. I’m assuming you don’t know how the pre section is wired.

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I believe the c3g are triode strapped. Another person suggested the c3g tubes can tend to oscillate and cause unwanted sound characteristics. He was adamant about removing the metal outers on the c3g, so i also want to try the one still with it’s jacket even if that shield probably wasnt meant to protect against oscillation.

Im going to see if i can reach out to the builder and speak to him about all the stuffs. He has been receptive previously so maybe we can dig more up.

Ill also say the Radu amp had c3g drivers and that was by far the biggest sounding amp ive heard. Different circuit, transformers, and that used 300Bs vs this one’s 2a3s but not totally apples to oranges.

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Oscillation is a term used to describe an unintended feedback loop, usually caused by a phase difference, in part it’s why you put capacitors on the input. If your source has a lot of signal outside the audible band you won’t directly hear it, but it can cause the amplifier to misbehave. That signal can also be caused by external RF.

Most amplifier circuits have some negative feedback at some frequencies even if it’s not explicit, if you look at a phase plot it’ll be close to 0 (or more likely 180) degrees in most of the audible range, but at very low and high frequencies it’ll swing, if that swing hits 180 degrees away from normal before it’s gain drops off significantly, your negative feedback becomes positive feedback, and your amplifier turns into a signal generator.

I’ve never removed the covers from my C3G’s, but it shouldn’t really matter, there is a way to ground the shield in the socket, but it’s rarely done, so it isn’t even a complete faraday cage, it probably helps if your picking up RF from somewhere but it’s not likely to be more prone to that than other tubes.

My limited experience with them is they are pretty well behaved and measure insanely well for linearity. I ended up using C3M’s in the hybrid (mostly for cost), which are a similar tube also designed for telecommunications use, though whith somewhat different characteristics, and an unusual 20V heater. Same shielding which I leave on.

There are a lot of ways to wire an input stage. So it’s hard to guess.
2A3 amps generally tend to be more linear and thinner sounding than 300B amps, but they can sound huge.

It’s worth noting on the interstage coupling capacitors, some expensive capacitors are known to un-break-in if they aren’t used for a while.

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