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They use 4 equal secondaries that can be combined in various parallel and series connections for multiple impedances.
Hmmm..... hadn't thought of that way to get impedance/load matching. Very Nice. ;-)
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************************************************* "The only difference between me and a madman is that I am not mad."
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TEAM MILLETT MAX - TEAM BIJOU
TEAM HEADROOM - TEAM β22
Yeah, I guess, but compared to a 50lb power supply?
Well, the problem is that it's kind of hard to eliminate the 50lb beast if you want to be able to run the amp at the current levels that I did and keep it tube rectified. The B+ needed to supply almost .4A of current at ~300V and there are three different heater supplies: 5V for the rectifiers, 6.3V for the input and 6.3V @10A for the output tubes.
Anyhow, I apologize for derailing the thread, so I'll leave it alone.
Actually, I think that the discussion is great. The design is a platform, not a directive so exploring options are a welcome addition. At one point I was actually considering a transformer coupled version but decided to stick w/ my original plan of a hot-rodded HA-2. I can't wait to hear Pete's new TTVJ trafo coupled design at CanJam.
Originally Posted by nikongod
very nice work nate. i like the layout a lot, and cant wait to see the inner-bits of the amp.
Thanks Ari, the layout was largely dictated by function, not form ironically enough. The PS layout is darn near a schematic in the way that it's put together. For the amp I knew certain things, like wanting to keep the heater wiring as far away from the signal path as possible, so I chose to have the heater wiring come into the chassis on the opposite side of the rear panel. For the amp I also went as far as doing CAD drawings of the layout and a wiring diagram to try and head off any potential problems. Those efforts paid huge dividends in the form of much less thought having to go into the wiring when I got down to business. And in truth the circuit is pretty straight forward and simple (low parts count) compared to a lot of the SS stuff that I've worked on.
Well, the problem is that it's kind of hard to eliminate the 50lb beast if you want to be able to run the amp at the current levels that I did and keep it tube rectified. The B+ needed to supply almost .4A of current at ~300V and there are three different heater supplies: 5V for the rectifiers, 6.3V for the input and 6.3V @10A for the output tubes.
eh? 10 amps? 2.5 amps per 6080 iirc.
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Team Planar | Team Sturzhelm | Team Cheap Bastards If the monster is immortal, either it does not exist, or there are two.
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AudioCubes2 declined to cancel my order, then lied to me and told me it had already shipped a full business day before the date on the shipping label.
I thought that I'd mentioned before but I just looked and I didn't - the amp was designed to be able to run at least 7 output tube options: 6AS7, 6080, 5998, 7236, 6528, 6336, 421A and I'm sure many others that I haven't found yet. The heater requirements range from a low of 2.4A (per tube) all the way up to 5A. I'm working through all the substitutes listed in Duncan's TDSL but for the 6080 alone there are more than 10 alternative tubes listed so I'm sure my wallet will give up long before I run out of tubes to try.
Well, the problem is that it's kind of hard to eliminate the 50lb beast if you want to be able to run the amp at the current levels that I did and keep it tube rectified. The B+ needed to supply almost .4A of current at ~300V and there are three different heater supplies: 5V for the rectifiers, 6.3V for the input and 6.3V @10A for the output tubes.
So, I guess the point I was trying to make is that there are 2 main ways to lower the output impedance (assuming no solid state buffers). One is to use brute force -- a stack of cathode followers, or something similar -- the other is to use impedance matching via a transformer. With the transformer, you wouldn't need the huge volume of tubes, and thus would save the expense of a huge power supply. A single 6H30 will power almost any phones to extreme volumes, for example.
Originally Posted by n_maher
I can't wait to hear Pete's new TTVJ trafo coupled design at CanJam.
I didn't know such a thing existed. I'm curious to see how Pete designed it.
Please do, as I said I'm no designer and contributed very little to this project from a design perspective. About all I designed was the heater biasing setup, which is really nothing more than a series of voltage dividers. I was rather happy that it actually worked.
I didn't know such a thing existed. I'm curious to see how Pete designed it.
I like OTL amps. pete's comment on good transformers having a good price is very true, but i agree with davistk's point of transformers doing cool things.
i still think the amp looks pimp, and if nate REALLY wants transformers they can always be run parafeed in a their own little case like moth used to do. its a nice project for a rainy day.
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Originally Posted by mkmelt
ACHTUNG - ALLES KOPFPHONERLISTENERS
Alles kopfphonerlisteners non-technischens! Das tubenmachine is nicht for gefengerpoken und mittengrabben. Oderwise is easy schnappen der springenverk, blowenfus, und poppencap, mit spitzensparken, und smokentubes. Geverken inside der tubenmachine is fur der experten only. Is nicht fur geverken inside by das dumpkopfen. Das rubbernecken amateuren keepen das cotton-picken hands in das pockets. Just relaxen, enjoyen der musik, und vatchen das pretty glowentubes.
But if the amp sounds half as good as it looks it will be a killer. Nice work!
Linear Mode
