Oh no. This is the last iteration, predicated on the Silk power tranny I can't get any more. The laytess bestess is the Antek above, but everything has its bright side, including the economic black hole that sees me still in posession of the proto since everybody's pinchin' every penny. I don't truck it out often, but a prospective wants to hear my sh!t tomorrow, and I'm warming it up. Now playing, Linda Ronstadt 'Adios', with Brian Wilson times three singing backup.
Wow,
Poinz
Wow,
Poinz
Poinz:
One more question on the PS; in the schematic you've got posted you have an Antek PT that I was shocked to find only runs about $30. On your website you've got spec'ed a Hammond PT that looks to be much beefier and runs in the neighborhood of $100. Do you really like the little Antek? I'd love to go with a $30 power tranny if you've gotten good results with one. I very much like the universal voltage feature as I move a lot.
Oh, one more thing, can you post the PS schematic with tube rectification? The one on your site looks to be stamped '06 and the one you posted here is stamped '08; just want to make sure I'm current.
One more question on the PS; in the schematic you've got posted you have an Antek PT that I was shocked to find only runs about $30. On your website you've got spec'ed a Hammond PT that looks to be much beefier and runs in the neighborhood of $100. Do you really like the little Antek? I'd love to go with a $30 power tranny if you've gotten good results with one. I very much like the universal voltage feature as I move a lot.
Oh, one more thing, can you post the PS schematic with tube rectification? The one on your site looks to be stamped '06 and the one you posted here is stamped '08; just want to make sure I'm current.
Last edited:
You should see the Antek; it's a brute. It's about five inches in diameter and weighs about seven or eight pounds. For power duty, I love toroids, I'm gonna use them everywhere I can. Because they're so magnetically efficient, they don't heat up or make much strayfield. The Hammonds, even the 3xx series, have always been somewhat of a problem, making a lot of heat on the chassis, and sometimes humming mechanically. Even the nice Silk gave me problems with this. I actually had to make a vacuum impregnation rig because it was such a problem.
For 10K output load, I operate the 6V6 at 315V(screen max) and about 35mA current. This results in near class A operation, with just a little single swing on the ends for transients like drum whacks. If you have an 8K load, you can lower rp of the tube a little by operating at, say, 295 or 300V and 39-40mA, which will lower the rp of the device to better match the load. You'll lose a little max power this way, but gain it back in the N of the transformer.
Aloha,
Poinz
AudioTropic
For 10K output load, I operate the 6V6 at 315V(screen max) and about 35mA current. This results in near class A operation, with just a little single swing on the ends for transients like drum whacks. If you have an 8K load, you can lower rp of the tube a little by operating at, say, 295 or 300V and 39-40mA, which will lower the rp of the device to better match the load. You'll lose a little max power this way, but gain it back in the N of the transformer.
Aloha,
Poinz
AudioTropic
Now I am curious Poinz, how are you powering the 5AR4 in the tube rectified version, dropping resistors, a separated heater transformer? The transformer covers on the newest iteration that you have shown, are they just covers or is the iron potted in them? Lastly, is the output still the same (the Silk) just with a cover, or something new?
The tube rectified version uses (used) either a 3xx Hammond or Silk power transformer, both of which had HT (tapped for bias), 6.3 and 5.0 volt secondaries. On the amp in the picture, all the iron on top is Silk, and the cover is an integral part of the transformer.
The new versions will have common covers, one on each side, containing various transformers. It'll look cleaner and more distinctive, and on the operational side will allow me to choose and mount various transformers underneath. In all cases, that mongo Antek toroid will go below the plate, inside the chassis. I may use Silk outputs, they're really good, but I've been talking to Mikey, and also I would really like to try some of Bud Purvine's stuff. I hear it's excellent.
Aloha,
Poinz
AudioTropic
The new versions will have common covers, one on each side, containing various transformers. It'll look cleaner and more distinctive, and on the operational side will allow me to choose and mount various transformers underneath. In all cases, that mongo Antek toroid will go below the plate, inside the chassis. I may use Silk outputs, they're really good, but I've been talking to Mikey, and also I would really like to try some of Bud Purvine's stuff. I hear it's excellent.
Aloha,
Poinz
AudioTropic
Well my first load of parts for this project has arrived. Some very nice Silk OPT's, some NOS Sylvania 6V6GT's, some NOS Hitachi 6GK5's, some GIANT Amphon (sp?) PIO caps, along with a couple odds and ends. I picked this all up from the Swap Meet section here and should hopefully be adding the rest of the parts in the next little while. Poinz' glowing recommendation of the Antek is pushing me in that direction but I think I'm sentimentally attached to the idea of tube rectification. 
Anyway, its coming together!
Anyway, its coming together!
Well you might just get to hear it too. I noticed your location as the Netherlands and I'm moving to Berlin in the next month or two. Maybe we'll have to get together.
So I've been looking at the new stuff I got and pondering how I'm going to put this all together and the thought has crossed my mind of doing two separate chassis; one for the power supply, one for the amp section, any thoughts? If I do go SS in the power supply with the Antek PT it could all go in a nice little enclosed box and then the amplifier section could sit on its own. Hmmm....
I have never built a two-box amp with the division being along the PS / AudioCircuit line. I would think that the umbilical and its connector(s) would be the matter. You got a bunch of stuff (B+, B+2, bias, tail-, heaters) coming through that cable, and having to terminate within a few millimetres of each other in the connector. A nice predicament.
P
P
separate chassis
I've thought about it also....and what concerns me is running AC heater lines with lots of current in the same umbilical as the B+ which you want flat as a pancake. Perhaps 2 umbilicals is the answer. I have a whole box of amphenol circular metal connectors with gold terminals that were scrapped from work saying "use me".
FWIW, I'm just finishing a monoblock version of Poinz' 6GK5/EL34 Machine and they are dead quiet on my 90db speakers. I just got the second channel up and wobbling last nite.
This is my second power amp project with the original baby huey being the first, so I will be comparing these two shortly. I have a small pile of 6GK5's, 6V6's and Hashimoto 8K transformers so the 6V6 version will be a project in the near future.
This has been a great project that just makes sense to me. PP triode fixed bias, two stage with a CCS, mostly class A, what more could you ask for? I have been taking a semi-newbie attempt at plotting load lines for both of these amps and figuring out how to care for and feed a 10M45S. So far a great learning experience, thanks Poindexter!
I'm presently also plotting load lines to see how much power one could get out of trioded KT88's using this topology.
I've thought about it also....and what concerns me is running AC heater lines with lots of current in the same umbilical as the B+ which you want flat as a pancake. Perhaps 2 umbilicals is the answer. I have a whole box of amphenol circular metal connectors with gold terminals that were scrapped from work saying "use me".
FWIW, I'm just finishing a monoblock version of Poinz' 6GK5/EL34 Machine and they are dead quiet on my 90db speakers. I just got the second channel up and wobbling last nite.
This is my second power amp project with the original baby huey being the first, so I will be comparing these two shortly. I have a small pile of 6GK5's, 6V6's and Hashimoto 8K transformers so the 6V6 version will be a project in the near future.
This has been a great project that just makes sense to me. PP triode fixed bias, two stage with a CCS, mostly class A, what more could you ask for? I have been taking a semi-newbie attempt at plotting load lines for both of these amps and figuring out how to care for and feed a 10M45S. So far a great learning experience, thanks Poindexter!
I'm presently also plotting load lines to see how much power one could get out of trioded KT88's using this topology.
Last edited:
The reason I'm considering the two box solution is that the Silk OPT's that I got are nicely potted and look very nice; the choke and Toroid don't look quite as nice. I'm trying to get creative on how I can make this thing look the part. A two box solution seemed like a slick solution and I wouldn't mind running two umbilicals but would for sure be open to other ideas.
Have all my bits and pieces, also for several months now. I picked the potted 25watt Hashimotos. Cool coincidence! And I think a two box is very possible.I need to go that route, I am using Motor Runs, and they just chew up to much room.
I'll use 3 different umbilicals keeping AC on its own. and running ground to and fro, in each different bundle. I know this makes for a large amount of wires and such but you should see the size the power supply needs to be, to hold all the cans. Once I got over the fact I wasn't building a sleek sportscar like Poinz, I became alright with everything else.
I'll use 3 different umbilicals keeping AC on its own. and running ground to and fro, in each different bundle. I know this makes for a large amount of wires and such but you should see the size the power supply needs to be, to hold all the cans. Once I got over the fact I wasn't building a sleek sportscar like Poinz, I became alright with everything else.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.