philodox

All I know is that because of the CCS and the negative supplies the tube has a constant current through it... which means it does not vary like it would if it had a plate and/or cathode resistor. Since every tube is slightly different [even between the same brand], in a tube amp that uses resistors on the plate and cathode, the current will vary through the tube which affects its operating points and changes the sound. Even though slight variations in sound might come from the construction and design of the tube, it is much less apparent [or perhaps nonexistant] with this type of circuit. Now, that is not to say that SinglePower amps are crappy due to the way they are constructed... but they are different beasts. If you like to change your sound by swapping your tubes, then a SinglePower amp might be preferable to you.

Good point, I will definately be trying tube rolling on my amp... just going to keep an open mind. I'm confident that if there is a change I will still notice it regardless of what Peter tells me, but by the same token I don't want to convince myself that there will be a change and imagine something.

According to Peter you shouldn't bother, but definatley try it out for your own piece of mind.

A better question might be, "why do alternately branded tubes of the same type sound different from one another"? If you can answer that question I may be able to squeeze out of Peter why these factors are not important with his designs. Or how he has gone about eliminating them. I do know that it is part of his design methodology and have talked to a few people who have purchased his preamps in the past and they tend to agree with them that tube rolling makes no difference on his amps.

Hmmm... I like them well enough with Bowls. recstar24 - Nice deal on that HD-25! I loved that amp, but it couldn't drive my K340's properly unfortunately.

I forgot to mention another tidbit. Hand wound transformer, with 8 seperate power supplies. I can't explain it as yet, but this is not what he is talking about. I know that part of it has to do with his fancy CCS, or 'infinite plate resistance' circuit as he calls it. Part of it might also have something to do with the negative supplies that he uses which allows the removal of the cathode resistor. As far as I know he is not using any sort of feedback loop. lol, I will try to get as much information out of him as I can. Damn, you're right. You'd better get on that!

It will be interesting to try a few different 6GU7's, as Peter says that there should be no difference when rolling different tubes in this amp. Something to do with his CCS design. We'll have to wait and see though.

Almost forgot: The 4 new tubes are 6GU7's, which are a lower gain version of the 6CG7's. He said that I can substitute CG's, but that I definately will not be needing that extra 3dB of gain. What is absolutely crazy is that only one of those tubes is for regulation and it has solid state rectification. All of the tubes are all duals, even the pentodes. Now, I know he uses a tubed CCS and is putting a tubed RCA->Balanced 'phase splitter' in there for the unbalanced inputs... but I'm having a hard time working out what exactly all the tubes are doing. I think he said the 6H30's are being paralleled, so that accounts for 4 tubes. Hmmm, I guess I will just have to wait until tomorrow night when he explains everything to me.

Well, I was supposed to get my new balanced McAlister Audio amp Sunday morning... turns out that the faceplate guy had issues with the green sublimation process. I decided to get the amps name in a forest green colour. Should have just left well enough alone! But then again, maybe not! I get a call from Peter on Sunday afternoon. He says he has been listening to my amp, and while it sounds incredible, he decided that he wants to go a little more 'over the top' with it. A man after my own heart. So, it looks like there will be 4 more tubes, for a grand total of 13... as well as two more metal can capacitors. He says that it looks like a BEAST. I can't wait to see it. Picking it up tomorrow night. PS. Just wanted to set the record straight. I made a comment in a previous thread about this costing 1/5th the price of the B52. I spoke with Peter, and he said that if he decides to market this as one of his designs it will likely run around $3k when all is said and done. Still, it is 3/5th the price of a B52.

Cute.

Nice impressions. I don't know enough about it's technical capabilities. My problem with this amp is the cost. Did it have a $5000 sound? If so, what are you comparing it too with a similar price tag?

Ummm... I'm going to kill you all tomorrow night in your sleep.

The Be Good Tanyas, with Old Man Luedecke opening. Before that Massive Attack. Next week I am seeing Imogen Heap again, looking forward to it.

WTF IS TOOLEAUDIO!?!?

Hmmm, that does sound like a good christmas gift. I'll have to start dropping tori amos hints at the Wife. I have everything except 'To Venus and Back' as I can't seem to find it for less than $30 used. I even have a CD called 'More Pink' that has tons of B Sides... I should burn you a copy of that Eaphan.

I know exactly what you mean, that absolutely killed me.

Are you guys listening to the stereophile test system? No, I didn't think so. There are fucking leprechauns mating all over that place. We cannot expect to replicate that situation. Damn my light is broken... too extreme tweaking!

Solid state rectification is just as good if not better. Sounds like the HD30 is a real winner.

buuhhh?

Wow, I need to read my posts before I hit that button. The above quote has been edited for clarity. neilvg - I know, it is hard to believe... but I've heard it.

Considering that a pimped out SDS-XLR costs $10k-$15k, I'm going to look at the value of the system here. In any case... I would rather get a HE90 and a cheaper amp than the O2, and as for the HD650. They are not the only dynamic headphones that sound better balanced. Hell, some headphones even sound good unbalanced.

I agree, the price is pretty crazy. I mean, my new balanced amp is going to probably cost me one fifth of that when all is said and done... and if it is not three or four times better than the B-52, I will be absolutely shocked. Thats some good math there.

LOL... good point, I missed that.

fugly

Fair enough... I wasn't aware you had an ES-1 on order. I think it is just a matter of taste in that case, as even balanced, the HD650 is really not my cup of tea.