[tdinut]

Hi,


Looking for any Audion owners and their opinion of the Black Shadow (or even Golden Dream) amps. I just recently discovered SET by buying the Line Magnetic LM-219IA. I am totally amazed and now SET obsessed. Any recommendations or help is much appreciated. Thanks!


http://www.ambienceaudio.com/product...uh#prettyPhoto

[tdinut]

Anyone have any other recommendations?

[FullRangeMan]

I like the 211, more gain and refinated than the 845.
If I had not a 6C33 I would like this plain simple chinese amp with the new black aluminium chassis:
http://www.mei-xing.com/english/English/cp/2_211.html
Its a modest amp, just one power transformer, solid state rectification, only 16W to long tube life and a smashing monoblock status with volume control to input a cd player direct;

Of course LM are much better than these Mings, but they have 845 amps to 20W:
http://www.mei-xing.com/english/English/cp/845-C%2020TH.html

[JoshK]

As someone who has studied tube amp design for many years and built tube amps myself, I highly recommend Thomas Mayer http://vinylsavor.blogspot.ca/.   His doesn't cut corners, use electrolytics and knows how to design well.   I own 211 monoblocks built by him.    On par price wise with the Line Magnetic series (I think) but way better parts on average.

[JoshK]

P.S.  I paid less than that for my 211 monos and judging by tube lineup, Thomas' design is a lot better design then using three stage based on small 9 pin driver tubes. 

[FullRangeMan]

P.S.  I paid less than that for my 211 monos and judging by tube lineup, Thomas' design is a lot better design then using three stage based on small 9 pin driver tubes.

I wonder why they apply 3 tubes if 2 are enough??
Do you would post any specs or photos from your 211 amp?

[tdinut]

Thank you Josh. I see he is from Germany.


Thanks.

As someone who has studied tube amp design for many years and built tube amps myself, I highly recommend Thomas Mayer http://vinylsavor.blogspot.ca/.   His doesn't cut corners, use electrolytics and knows how to design well.   I own 211 monoblocks built by him.    On par price wise with the Line Magnetic series (I think) but way better parts on average.

[Hugh]

Head over to Audiogon and ask Phil (213cobra) for his opinion.
Phil has the Black Shadow and he likes it a lot.
We did a comparison at his house between his Black Shadow and our Melody M845 Monos.

http://forum.audiogon.com/cgi-bin/fr.pl?cspkr&1360136859&&&/Zu-Druid-Definition-Roundup

[JoshK]

The thing I like about Thomas is that for all but his most exotic designs he shares with your the circuit, so you can see for yourself that it is very well designed (that is if you know design).   Second link shows the design.  Its about 30watts from the A2 operation (courtesy of the interstage transformer).

http://vinylsavor.blogspot.ca/2012/11/making-of-211-vt4c-mono-amplifiers.html
http://vinylsavor.blogspot.de/2011/03/making-of-211-amplifier-part-1-planning.html
http://vinylsavor.blogspot.de/2011/03/making-of-211-amplifier-part-3.html
http://vinylsavor.blogspot.de/2011/03/making-of-211-amplifier-part-2-assembly.html

He shipped them to meet in wooden crates he made for shipping, they arrived safe and sound.   The four chassis version was his preference since they are easier to move, the mono blocks are ridiculously heavy.  But I liked the looks of the mono blocks, so I opted for them.  He also let me chose any wood/color I wanted.  I went with utilitarian black. 

[JoshK]

I wonder why they apply 3 tubes if 2 are enough??
Do you would post any specs or photos from your 211 amp?

Well not many tubes out there can drive a 211 with just one driver tube.  He found a very interesting triode used in (iirc) radio transmitters that has a mu of 300!  Given the super high gain, he uses a step down interstage to convert the extra gain into current drive that lets the 211 draw current in A2.  Its really a clever design and much more clever than the bog standard ways used with small 9pin tubes.

[JoshK]

For the record, some of the commercial amps that I seem to like in terms of the perceived design and build quality include Line Magnetic, Melody Audio (higher end stuff) and a few others. 

Realize that the driver in a SET amp contributes as much if not more than the output tube despite the optics.   This means that the driver stage is very critical to the sound.  I am not ripping on Black Shadow, the 5687 variant (E182CC) is amongst the most capable 2nd stages of the 9pin family, but that still means they have to use 2 stages and voltage swing for the 5687 will be marginal for full 845 output.   Again, I haven't see the circuit details or heard the amp, just judging by what I know about tube designs.  I've sketched quite a few paper designs for the 845 and similar tubes, so I know the requirements.  (I am a bit intimidated to play with >1kv B+, so I let Thomas build mine).

[FullRangeMan]

Well not many tubes out there can drive a 211 with just one driver tube.  He found a very interesting triode used in (iirc) radio transmitters that has a mu of 300!  Given the super high gain, he uses a step down interstage to convert the extra gain into current drive that lets the 211 draw current in A2.  Its really a clever design and much more clever than the bog standard ways used with small 9pin tubes.

Nice. Do your 211 amp is that with 5 chokes?
The driver is a 2A3, 12ax7/au7 are gain in the preamp stage.

[Soothsayerman]

Those look incredible!

I'm not sure I understand why so much capacitor storage though, is it because there is only the one 211 per channel providing output current?

The thing I like about Thomas is that for all but his most exotic designs he shares with your the circuit, so you can see for yourself that it is very well designed (that is if you know design).   Second link shows the design.  Its about 30watts from the A2 operation (courtesy of the interstage transformer).

http://vinylsavor.blogspot.ca/2012/11/making-of-211-vt4c-mono-amplifiers.html
http://vinylsavor.blogspot.de/2011/03/making-of-211-amplifier-part-1-planning.html
http://vinylsavor.blogspot.de/2011/03/making-of-211-amplifier-part-3.html
http://vinylsavor.blogspot.de/2011/03/making-of-211-amplifier-part-2-assembly.html

He shipped them to meet in wooden crates he made for shipping, they arrived safe and sound.   The four chassis version was his preference since they are easier to move, the mono blocks are ridiculously heavy.  But I liked the looks of the mono blocks, so I opted for them.  He also let me chose any wood/color I wanted.  I went with utilitarian black.

[poseidonsvoice]

For the record, some of the commercial amps that I seem to like in terms of the perceived design and build quality include Line Magnetic, Melody Audio (higher end stuff) and a few others. 

Realize that the driver in a SET amp contributes as much if not more than the output tube despite the optics.   This means that the driver stage is very critical to the sound.  I am not ripping on Black Shadow, the 5687 variant (E182CC) is amongst the most capable 2nd stages of the 9pin family, but that still means they have to use 2 stages and voltage swing for the 5687 will be marginal for full 845 output.   Again, I haven't see the circuit details or heard the amp, just judging by what I know about tube designs.  I've sketched quite a few paper designs for the 845 and similar tubes, so I know the requirements.  (I am a bit intimidated to play with >1kv B+, so I let Thomas build mine).

Very much agreed. Notice how Kevin Carter does the same!

Best,
Anand.

[JoshK]

I'm not sure I understand why so much capacitor storage though, is it because there is only the one 211 per channel providing output current?

That row of caps are 5uf/2kv paper in oil caps. 

Each of the 10uf caps in the schematic are two 5uf in parallel, so that is 10 caps.  2kv paper in oil caps are big!

[JoshK]

Nice. Do your 211 amp is that with 5 chokes?
The driver is a 2A3, 12ax7/au7 are gain in the preamp stage.

Yeah, this amp has 5 chokes and 4 transformers.  They are beastly heavy.

Which amp has 2a3 driver/12a*7 gain?  NM, it was the mingda you were referring to.

[FullRangeMan]

Yes it was the Ming.
Your amps looks expensive, I would like to listen it.

[Soothsayerman]

That row of caps are 5uf/2kv paper in oil caps. 

Each of the 10uf caps in the schematic are two 5uf in parallel, so that is 10 caps.  2kv paper in oil caps are big!

Ah gotcha, thank you so much for the explanation, they are huge. 

[rodge827]

Those look incredible!

I'm not sure I understand why so much capacitor storage though, is it because there is only the one 211 per channel providing output current?

How can one obtain these or any of his other amp builds?
Any idea of the cost in $US for the 211's shown?

Curious,

Chris

[JoshK]

How can one obtain these or any of his other amp builds?
Any idea of the cost in $US for the 211's shown?

Curious,

Chris

You just have to send him an email.  He gave me an estimate of how long it would take as each is custom made point to point wired by himself and it isn't a full time gig, just a side business.    If you ask him how much, he will tell you and can also suggest designs that may be more or less affordable depending on your budget.   Those above aren't cheap but given the components involved in that design, very reasonable and a much better value than any other design I have seen that is comparable.