[roderickvd]

I have different audio gear with linear PSUs and none of them hum. Just to rule it out, I installed a DC blocker before my H7mk2 and it made no difference. With Wieslaw's permission, I opened my unit and superglued the outer laminates which I found out had some room to wiggle. Again no difference.

It was at this point when Wieslaw said to me "transformers should not hum" and he offered me to put in some other one for free, alongside shielded cabling. Great service and I will be keen to learn what he is putting in now.

 

[moriez]

Thanks for the transformer suggestions. I'll take it to him alongside pot and any smaller parts that might be of better quality.

@kvik
Your mention of 24 steps being too few is a good one. How did it turn out?

 

[kvik]

Thanks for the transformer suggestions. I'll take it to him alongside pot and any smaller parts that might be of better quality.

@kvik
Your mention of 24 steps being too few is a good one. How did it turn out?

I settled on TKD (again), the stepped attenuators (Khozmo, Elma, Goldpoint, and Acoustic Dimension) became a bit to pricey for me, as I needed two stereo pots. If you are asking about the amp in general, it has a dedicated, danish thread Google Translate butchers the language, but you might still get some idea (and there are some useful 4P1L links in there). I believe mine is the version without voltage amplification. I still need to acquire a balanced source, so haven’t fully explored the amp yet.

 

[moriez]

What I was getting at is the attenuation jumps. Your post reminded me of how half of the time I wanted in-between increments with my previous amps.

 

[g0ldl10n]

Dual 24 strapped tetrodes as input stage, followed by RCA 6336A as output on H5M (obviously running each stages heaters off external power supply) sounds heavenly!

Oh, what I would do for a customized H5M that can handle the amperage requirements from all 3 tubes here + being able to adjust input stage voltage to what's needed for the 24s, at 2.5V.

Think I will reach out to Wieslaw to see if this is something that may be possible.

If you are using external PS to run different tubes, highly recommend checking out the 24s and 24A tubes!

 

[mordy]

Dual 24 strapped tetrodes as input stage, followed by RCA 6336A as output on H5M (obviously running each stages heaters off external power supply) sounds heavenly!



Oh, what I would do for a customized H5M that can handle the amperage requirements from all 3 tubes here + being able to adjust input stage voltage to what's needed for the 24s, at 2.5V.

Think I will reach out to Wieslaw to see if this is something that may be possible.

If you are using external PS to run different tubes, highly recommend checking out the 24s and 24A tubes!

That would be a pretty hefty amp capable of 8.5A...

 

[triod750]

Make it a dual mono!
17A would make for a warm room...

 

[g0ldl10n]

That would be a pretty hefty amp capable of 8.5A...

Yep, this is true - I am obviously not an amp builder, but do you not think that is possible?

The H22M is running two 6AS7 and two 6SN7. Not quite as much, but its getting up there. Maybe not, idk.. but would be lovely nonetheless

 

[g0ldl10n]

Dual 24 strapped tetrodes as input stage, followed by RCA 6336A as output on H5M (obviously running each stages heaters off external power supply) sounds heavenly!



Oh, what I would do for a customized H5M that can handle the amperage requirements from all 3 tubes here + being able to adjust input stage voltage to what's needed for the 24s, at 2.5V.

Think I will reach out to Wieslaw to see if this is something that may be possible.

If you are using external PS to run different tubes, highly recommend checking out the 24s and 24A tubes!

Oh, and I should add - anyone not running external PS, some tubes which are literally a dime a dozen in NOS/NIB/JAN condition that sound nearly as good, are the 39/44 or VT-49. These require typical 6.3V and only 0.3A, and you run them as pairs, using the same adapter.

I have NU and RCA types as of now - I favor the NU variants, but both are good. I have some TS variants on the way - will update with how I like them.

EDIT: I just wanted to add - H5M sounds really damn good with a ridiculous amount of different input tubes granted you have the adapters, and or needed external PS for the heaters. To my ears, this design seems pretty darn good, if I must say so myself

 

[mordy]

Yep, this is true - I am obviously not an amp builder, but do you not think that is possible?

The H22M is running two 6AS7 and two 6SN7. Not quite as much, but its getting up there. Maybe not, idk.. but would be lovely nonetheless

It is entirely possible. I have a Glenn OTL amp with a 13A Lundahl transformer and if I add fan cooling I could run up to 14A of tubes. I believe that Eufonika uses Polish made transformers but it should be well within reach to build an amp with greater current capacity.
Regarding a built in voltage switch for 2.5V it may be trickier since the different voltages have to come from the transformer windings. (The Glenn amp has a switch for 6, 12 and 25V.)
Regarding the question if an amp with more than two dual triode sockets would sound better I don't know the answer. It seems to me that most high end amps have four sockets or more.

 

[g0ldl10n]

That would be a pretty hefty amp capable of 8.5A...

I have been in contact with Wieslaw, and he said he is gonna get a prelim design + quote done for me on an amp with such built-in capabilities. Also, asked to have an additional output specifically for lower impedance headphones as well, which he said could be done too.

So, an amp with this built-in capability, would be truly amazing! Endgame level for me for sure!

 

[mordy]

I have been in contact with Wieslaw, and he said he is gonna get a prelim design + quote done for me on an amp with such built-in capabilities. Also, asked to have an additional output specifically for lower impedance headphones as well, which he said could be done too.

So, an amp with this built-in capability, would be truly amazing! Endgame level for me for sure!

Sounds very interesting! And knowing Wieslaw the price most likely will be reasonable…

 

[PiotrekS]

I bought H5KPCU, among other things, thanks to reading this thread. After a week+ came the amplifier. I turned it on, I listened. He played poorly - kind of blanket. After four hours, it burned. The stench went and turned off. Something like wax poured out of the inside. I sent the amplifier back to Mr. Wiesław. After a week I got a repaired amplifier with instructions not to put the 6080 tube to the end and leave 1-2mm gaps. So I did. I turned it on - he played much better than before.
But in general, the midrange was too weak, the bass slightly spilled and not controlled.

I bought a Tung Sol 6f8G VT-99. Diameter and space appeared. Then I bought RCA 6as7g and controlled bass appeared. Now it is really very good. The amplifier with RCA 6as7g does not heat up. Depending on which source I listen to, I have minor differences (CD Lector on ECC801S, TDA1541 with 6N16B+6N2P-EW and Mytek Libert II DAC on ESS9038).
To sum up, for 700 Euro (Amp and great tubes) you can have an absolutely cool headphone amplifier that sounds great, where tubes can shape the sound and it looks like a million bucks
My headphones are HD8xx.

 

[g0ldl10n]

I have been in contact with Wieslaw, and he said he is gonna get a prelim design + quote done for me on an amp with such built-in capabilities. Also, asked to have an additional output specifically for lower impedance headphones as well, which he said could be done too.

So, an amp with this built-in capability, would be truly amazing! Endgame level for me for sure!

Well, I am very happy to announce Wieslaw is going to begin working on this amp for me at a very reasonable price!

This type of capability built into an amp is going to be amazing IMHO. Essentially, seems he's just gonna take the H5M and build these modifications/capabilities into that, which is exactly what I was looking for actually!

Will end up having two voltage regulators with digital displays built-in, which I will be able to adjust within a 2V-30V range, which suits my needs just perfectly. Also, discussed the need to have it be able to run dual Type 24 inputs + 6336/6528 output, which is quite a bit of current to handle there, which would be the very high end of current from any combo of input/output tubes I will be running.

I really can't wait to be able to get rid of these ugly adapters with wires running to my external PS, super eyesore, but I am glad I did this, otherwise there would be many tubes I would have never tried - so in the end, it was all worth it.

Shoutout to @mordy for pointing me in the right direction to get my external PS setup with my H5M - your insight/help is always appreciated!

 

[triod750]

So will you be able to run the input at one voltage and output at another?