philodox

I'm surprised Larry didn't recable them... Still, that wood looks hott!

Oh, I see... well, I will say again: "this is all in my words and taken from memory and sketchy notes"

How can you be so sure when you haven't seen this part of the circuit yet? - Edit: Sorry, just noticed your bracketed comment. Please explain...

Ok, so here is what Peter said about the design to the best of my memory. Also keep in mind that he is forced to dumb down things quite a bit for me to follow. - 6BZ7/6BQ7A are on the input in paralled and are setup in a 'proprietary circuit' that provides ~6db of gain and has the primary purpose of presenting 100ohms impedance to the rest of the circuit, regardless of the impedance of the source. Three seemingly contradictory statements, but perhaps not: - 6CG7/6GU7 are in parallel and work in conjunction with the 27GB5/PL500 for the output. - The 27GB5 are in a way setup to be the CCS for the 6CG7. - If you want to say one tube is on the output, it is the 27GB5. Again, this is all in my words and taken from memory and sketchy notes. Someone was asking me the output power of the amp recently... can't remember who. Anyways, he said that if you were to give it a wattage rating, it would be 6 watts. He also said that is not the best way to rate the power of a headphone amp since it tells you hardly anything about its ability to drive various headphones. He said a better way to put it is 98volts peak to peak. When I asked him about current, he said that it could put out 600mA at 100volts easily enough. I asked him about output impedance again and he gave me the same answer, 40ohms. Hope that helps. We will know soon enough once I get Kevin to look at some pictures. EDIT: He also said that the 27GB5s are in triode mode.

You are probably right, but that IS a guess... right now anyways. "or a complete abortion like that wood thing that jason built" - Huh? Are you talking about the power supply for my prototype POS amp? The amp was actually on a scrap piece of plexi, get it right! EDIT: Go to the 'Hell hath frozen over' thread for info on what Peter told me.

That is a lot to digest... and I really should be working right now. I will be back later to respond in full. I also have some info from Peter regarding the design that I will share to the best of my ability.

hehe... Kevin Gilmore is my hero.

Exactly! Cry me a fucking river.

Cool... glad to hear it as the charlize I am building for my Polk Audio RTi4's [97db] is very similar.

I'm always loosing my crunchiness. ...shit, there it goes again *whistle* *whistle* Here boy!

I am surprised that the RWA Sig 30 gets so much praise given what it is inside it...

Here are some pictures of the 'finished' amp. There are still some aesthetic changed that I will be making - namely the faceplate. ...like I said, that faceplate just must go. ...I love the look of this tube. ...lights out. I can't wait to get a tripod so that I can take a more detailed picture of this type.

Nate - It is funny, but when I went to the tube store yesterday the guy there suggested the same thing when I mentioned that the 6BZ7's seem to be microphonic. He suggested just taking one of the tubes to home hardware or canadian tire and testing it out for the right size there. Combine that with the Jenga blocks tip that I got at the audio store the other day and it is looking to be 'budget upgrade week'.

Thanks Nate, that is exactly what I was thinking... found some dampers at the place I am going to this afternoon [thetubestore], but they are crazy expensive.

No time for pics yet, but it sounds great. Seems to be more bass. Front panel is still as ugly as sin, but hopefully swt61 can help me out with that. I still get a slight ~sort of ringing sound~ in either earcup on occasion... but only noticeable when nothing is playing. I'm thinking it might be tube microphonics but am not positive. The sound is very textured and the imaging/soundstage is just like I remember. I can't wait to hear it with my zapfilter modded CD-E5 [just waiting on a new transport] as I expect that will add the needed detail in the bass and overall speed.

The Tube Store is here in Hamilton... I am thinking about swinging by today if they will have me.

It was definitely a great time. I loved his comment after 'Group Four' finished... he said, "Why can't I walk into a room at an audio show and hear someone playing that instead of Norah Jones?" PS. The amp is back and in working order. Not to downplay the fun I had with those speakers, but Massive Attack is most definitely not ruined for me.

Good movie, that creepy Baldwin is always listening to Massive Attack in his little room.

Yes, that is what I meant when I said it has ruined Massive Attack for me. I suspect, though I can't confirm without my amp, that everything will sound second best for the next little while after hearing that amazing setup.

It's true. I heard Massive Attacks Group Four on a pair of $12k speakers in an absolutely insane setup... Audio Aero CDP [i think], EAR preamp and Gamut power amps. With all sorts of power/RFI tweaks of course, not to mention the room treatments. I am not sure which brand the speakers were, but I am sure that Eaphan knows. I got a little taste of vinyl, which was great and think I will be buying a Debut off of the dealer at some point. I happen to have 4 6H30's that are not in use at the moment and am presently looking for DIY phono stage designs. I will be getting my Amp back tomorrow night and am hopeing that I haven't really been ruined by that hi-fi rig I heard. Peter got it fixed up incidentally. Apparently some sort of grounding issue or something... all I know is he said it had something to do with the LED, the faceplate and the input stage. Figure that one out. Anyways, he listened to it for 3 hours last night after he got it fixed up and said to me, "You know, these headphones of yours are really good." I had a great time at the shop. I still can't believe the time warp we stepped into. I swear we were in the place for an hour or so, but it was 5pm when we entered and 10pm when we left. - Jay

oooooooooo The evil in me sort of wishes that he doesn't send it to you.

Well, mine is a dynamic amp... but I think it is safe to say I will not be buying another amp from him. The only saving grace is that it sounds great and was *very* cheap. After all the time it has taken the deal seems a bit less attractive though.

I just want my amp to work. Fuck, it sounded great before when the 6H30's were not even hooked up! That said... If I get it back and he throws me any lies about the design and when we open up I see those lies, that will be the time for slander. I am not going to ruin him for being a procrastinating ass. But I will not be lied to.

Yeah, Kevin knows what he is talking about... the 6H30's were not hooked up originally. This is primarily what needed to be 'finished'. My guess is that these 6BZ7's are on the input or used as a CCS or something like that. But, all that aside [no point in figuring it out before Kevin takes a look at some updated pics and draws it out] I got the amp last night... and the right channel was fucked. Swapped all the tubes and it was still pooched. Called Peter and he picked it up from Renato today and will [apparently be dropping it off tomorrow afternoon... or was that thursday?] weeeeeeee KG - "Similar in design to another tube amplifier well liked around these parts." Which one? And Earl, any recommendations for 6BZ7's? Are 6BQ7A's equivalent? From what Kevin told me, the 6BZ7's are a higher gain version of the 6922. Is this a bad tube if it is used on the input or somewhere else? Am I correct that you only thought it was bad since you thought it was used on the output?

Hey all, Just heard from my friend Renato [looser101] and Peter has finally dropped my amp off to him, so I will be getting it back tonight. I'll be sure to take pics and let you know how it is and if there are any improvements. Apparently the faceplate still looks pretty ghetto, but I will be having a nice wood one made by Steve [swt61] anyways. Now on to the tube question: He has removed the 4 6H30's from the amp and installed 4 6BZ7's. I haven't talked to him about this, so I don't know the reason, but I am sure he will explain it to me tonight... though I doubt it will make any sense. Anyways, what do you know about hte 6BZ7? What brands would you recommend? Any other tubes that are equivalent to it? Thanks in advance, Jay