Thanks for that link. I have some Promedia 4.1's that have a little noisy volume control, and also any time it's ever unplugged, after plugging it in the speakers make constant static noise for hours and hours, that goes away when I 'turn off' the pod (really just mutes it according to those...

From my experience with Edcors, the output transformers (XSM's in my case) are quite magnetically 'active' if you will. They are VERY susceptible to external magnetic fields (was seriously affecting my dynamic range/SNR in RMAA until I moved the power supply 2-3 feet away). Also mine 'sing' like...

  Finally did a test fitting of my amplifier. Should hopefully be able to listen to/RMAA it sometime next weekend! (time permitting). I had this cool old CATV amplifier extrusion case that has a full RF shield/seal around it, so I'm going to use that (the PCB's *barely* fit, I had to file them...

Well it IS a scope and it does work, but at that price I think I'd much rather buy a new baseline model like say the GW Instek GDS1072 or something...     We used the 97's in our industrial equipment lab at school, and I got the feeling they were much more geared to that purpose, providing...

Interesting.   Actually my favorite part of the whole thing might be the form factor. Most true tube amps are large, wide and boxy shaped. Doesn't sit well on a desktop next to a computer. My next amp I've been trying to make into a more long and skinny shape, though probably a good deal...

Also interesting, these are dual triode tubes. Are the sections being paralleled or does it just use half the tube? If so, is there any way to switch which section is used?

dsavitsk, DC heaters? I see what looks like a second bridge rectifier in there. And is there a reason you return the opt to ground instead of the cathode?   Those custom opt's from edcor look just great.       Oh and offtopic, on your site, the HPDAC6 page is missing.

Was the Hakko used? The temperature settings on most irons need to be calibrated, so just because it says 300C on the front doesn't mean the tip is anywhere near that. I'm curious to hear what you got on the temp probe.  

First off, as Avro asked, let us know what kind of solder you're using. Lead free can be a hassle. The easiest to use is 63/37 with a rosin activated (kester 44) or mildly activated (kester 285) flux core. 60/40 is acceptible, but there are lots of crazy combinations out there that range from...

I'm planning to try out a RMA solder next. I've always used kester 44, but I'm getting sick of the huge amounts of flux residue left behind. I know they say it's safe to leave on, though I don't see how that's possible for an RA flux, but even so it looks horrible. I don't trust no-clean solders...

The supply is split +147/-86, ground is just a reference voltage set by CCS-loaded gas discharge tube, and I might replace that with a simple resistive divider if I can't quiet down the discharge tube. But they are so pretty!   It is differential push-pull. The XSM 10K:38 carries ~23ma per side.

Little experiment.     According to rightmark the noise floor is really high, I believe the gas discharge tube needs a bypass cap, I just have to dig out one of my old russian teflon 0.056uF's. Also the 120Hz is poking out of the noise floor as well, so I might need another LC stage, or...

You don't think there's a big difference between the Raven and the hybrids?   What tubes are you using in the raven?   Also, as far as I knew, this is a raven: http://www.nutshellhifi.com/Raven-MarkII.gif   The k and k audio design you have linked in your sig is very different.

There's nothing wrong with the millet (or any other) hybrids, but they are not going to sound anything like a normal tube amp with transformer output coupling. I'd be hard pressed to even call them 'tube amps' really.

    Well, if you want to choose all the components, that's not really a kit. Are you just looking for a good design?   Without any solid state components, you need to use good single-ended transformers (or go balanced), and things can get expensive fast.   With solid state current...

When I did a ton of 20 gauge enamel hookup wire for my old headphone amp, I took a cheap rat shack soldering gun (with the loop element and trigger), and put a blob of solder right in the 'nook' of the heating element, and used that to burn off the enamel. It heats up in only like 5-10 seconds...

Speaking of multimeters, do you guys think its better to try to go better than 1% accuracy, or maybe get one with more features (relative measurements, PC interface, freq/duty cycle measurements and the like).   It seems hard to get much better than 1% below $100 anyway.

Quote: Originally Posted by nikongod A "disadvantage" of parafeed (its all perspective) is that the amps typically require a big fat coupling cap. Its usually between 3 and 20uf: Not so large that you cant use a film cap, but large enough that truly fap-o-matic types (teflon &gold...

Yeah the simplest method is to use a nice slow warm-up tube rectifier. Damper diodes are especially good.

Quote: Originally Posted by nattonrice I wouldn't put very much stock in anything that guy says. If it doesn't have a tube somewhere in it then it must be teh suck. I don't really know this guy so I can't speak directly to this case, but you sure don't have to be nuts about...

Quote: Originally Posted by Koyaan I. Sqatsi I've been designing using high quality microphone step-up transformers for voltage gain for years and when used within their limits, I'll take a good quality transformer over any active solution. se Steve?

Just for discussion's sake... if you had a 30v circuit w/ virtual ground, and a power supply in the 35-45v range, are there any things to really watch out for in the regulator? A 317 or 1085 can handle 30v in-out but I always figured there would be startup/shutdown issues depending on how...

Obviously not...

Is that solid state rectification, cetoole? I can't see the diodes.

What is this for? I had the impression you were working on a lesspressivo, not a cathode-follower amp. In which case you need nowhere near that much capacitance.