More tubes! Yeeeeee-HAW!

[philodox]

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.

[philodox]

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.

[Guest sacd lover]

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.

I like the 6gu7's. I have been using them for gain with my SP amps. The 6gu7 has an airier sound than the 6cg7 and is one of the most detailed tubes I have tried. The sylvania 6gu7 is very fast, clean and on the bright side. The RCA 6gu7 is a warmer tube but remains very detailed. The GE 6gu7 is somewhere between the other two. By the way, the 6gu7 is essentially the 6 volt version of the 12bh7. Why its not called a 6bh7 .... who knows?

[philodox]

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.

[Guest sacd lover]

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.

Unless he has a feedback loop that squeezes out the differences the 6gu7 tubes sound noticeably different from one another .... especially the contrast between the Sylvania and RCA.

[aerius]

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.

See if you can get a rough schematic off him, or I'll take your amp apart at the meet and trace the circuit out myself!

Which reminds me, I need to build myself a 4-pin XLR to whatever output jacks your amp has so I can use my K340 with your amp at the meet.

[philodox]

I forgot to mention another tidbit.

Hand wound transformer, with 8 seperate power supplies.

Unless he has a feedback loop that squeezes out the differences the 6gu7 tubes sound noticeably different from one another .... especially the contrast between the Sylvania and RCA.

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.

See if you can get a rough schematic off him, or I'll take your amp apart at the meet and trace the circuit out myself!

lol, I will try to get as much information out of him as I can.

Which reminds me, I need to build myself a 4-pin XLR to whatever output jacks your amp has so I can use my K340 with your amp at the meet.

Damn, you're right. You'd better get on that!

[philodox]

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.

[NotoriousBIG_PJ]

Yeah I'm going to be in downtown hamilton this sunday picking up my amp. Yeah I'm going to check out that little monster of yours . Yeah.

Biggie.

[aerius]

Yeah I'm going to be in downtown hamilton this sunday picking up my amp. Yeah I'm going to check out that little monster of yours . Yeah.

Biggie.

I don't think he's going to make it back to Hamilton by Sunday, he'll probably end up getting wasted at the meet on Saturday and end up crashing on the Subway.

[Guest sacd lover]

A better question might be, "why do alternately branded tubes of the same type sound different from one another"?

Because they were made with different materials, designs, constructions and trade secrets.

[philodox]

Because they were made with different materials, designs, constructions and trade secrets.

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.

[NotoriousBIG_PJ]

Hey, how bout giving a brother some love with a sunday evening demo. ^^

Biggie.

[philodox]

Unfortunately I have a dinner at my Dad's Sunday evening... If you leave me your cell, or PM me for mine it might work out, but I can't make any promises.

Reks - Yeah, I can definately see the benifits. Here is hoping I like the amp the way it is. Unfortunately there has been another delay... looks like Peter will be delivering the amp to me on Thursday.

[tkam]

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.

Nice! There can never be too many tubes.

[NotoriousBIG_PJ]

Unfortunately I have a dinner at my Dad's Sunday evening... If you leave me your cell, or PM me for mine it might work out, but I can't make any promises.

Ahh my amp starting crapping out on the left side like it did at your headphone meet a couple of weeks ago, so I sent it to DTS Audio in hamilton for repairs. Well he has looked at the amp and says its running perfectly and he can't get the amp to fail lol... I just know its going to start crapping out again at some point down the road though grrrrr.

Biggie.

[philodox]

Ahh my amp starting crapping out on the left side like it did at your headphone meet a couple of weeks ago, so I sent it to DTS Audio in hamilton for repairs. Well he has looked at the amp and says its running perfectly and he can't get the amp to fail lol... I just know its going to start crapping out again at some point down the road though grrrrr.

Man, that sucks. Must be sort of like when people at work have me take a look at their computer... then when I leave it starts acting up again. Chalk it up to gremlins.

I will PM you my cell phone number and you can call me on Sunday when you are thinking about leaving. I should be able to let you know around when I will be getting home from my Dad's. It shouldn't be too late, and I get Monday off [Remeberance Day... you gotta love the gov't] so if it works out you are welcome to come and don't need to worry about staying too late.

[NotoriousBIG_PJ]

I replied to your pm. ^^

Biggie.

[philodox]

Well, I've got a quad of matched Sylvania's and a quad of matched RCA's on their way to me. We'll see how she tuberolls.

[pabbi1]

The EA-6 rolled pretty sweet with the Raytheon short getter 6cg7 recommended by Hirsch - especially compared to the mix and mismatch tubes sent with it... good tubes always play better than, well, crap.

[Guest sacd lover]

Well, I've got a quad of matched Sylvania's and a quad of matched RCA's on their way to me. We'll see how she tuberolls.

6cg7 or 6gu7?

[philodox]

6cg7 or 6gu7?

6GU7... I figured that based on your description of the two they would be the perfect test to see if she tuberolls well. I'd also like to try those Raytheon 6CG7's at some point as everyone seems to be going crazy over them.

I got a good deal on the tubes I think... two matched quads of 6GU7's plus shipping for $40.

[Guest sacd lover]

6GU7... I figured that based on your description of the two they would be the perfect test to see if she tuberolls well. I'd also like to try those Raytheon 6CG7's at some point as everyone seems to be going crazy over them.

I got a good deal on the tubes I think... two matched quads of 6GU7's plus shipping for $40.

In the US .... the Raytheon, true USA made, blackplate 6CG7's, are very hard to find. The Raytheon 6CG7 you typically see is the Japanese version.

[hirsch]

In the US .... the Raytheon, true USA made, blackplate 6CG7's, are very hard to find. The Raytheon 6CG7 you typically see is the Japanese version.

The Japanese tube is the one I normally recommend. I prefer it to the US blackplate version. It goes deeper, and is not as dry sounding as the US tube. The Japanese Raytheon (I've seen them sold as Toshiba's, and that may be the real manufacturer), is one of my favorite 6CG7's, and outperforms some of the premium brands, such as the Mazda-Brimar or RCA cleartop, IMO. It's also very common and inexpensive, which makes it a gem.

[philodox]

I'm going to see if I can get a set of the Raytheon 6CG7's when I take the amp back to Peter's for the final touches.

I also found out that though 6GU7 is the tube he plans on using in the end, there are actually 6CG7s in there right now... I guess I could have figured that out myself by reading the writing on the tubes.