Well guys, my amp finally came in.

[philodox]

Sorry for the quality of the pictures... I really need to get a tripod.

A few points:

- Yes, the 1/4" jacks are different. Yes, it will be fixed.

- The Power keystart switch failed and Peter had to bypass it... I'm glad this happened before he handed the amp over.

- The faceplate didnt really turn out as Peter and I wanted it. Neither of us payed anything for it though so no harm. Steve [swt61] should be able to remedy this for us in any case.

- The XLR jacks are way too close to the volume knobs... this is one of the things that we will try to remedy with the new faceplate.

- I believe Peter mentioned that there is some more exterior finishing that is still to be done.

- Will probably swap the blue LED for a green one. Though I suppose I need to consider what will look proper on a bloodwood and ebony faceplate.

- I'm thinking about trying to source the aluminum caps voodoochile used in his gorgeous amp as mine are tin. With aluminum I could polish them up nice and clear coat them.

- We will likely tweak the circuit some more, though at the moment my complaints are very minor.

- It's still burning in, so no impressions yet.

My attempt at a Lights Out shot without a tripod...

Renato enjoying himself...

The whole rack...

[i know, this is a terrible picture.]

Random decent shot I took of the E5 Sig...

Peace...

I'm listening to Theivery Corporation - Heaven's Gonna Burn Your Eyes at the moment, and I swear, it is.

[909]

That amp looks fascinating. 13 tubes, five of which have those white caps on top. Those metal disc plates that surround each tube with holes drilled all around. I?ve never seen anything like it before. It?s pretty awesome looking with a straightforward scientific flare to it. I like that you have to turn the key to turn it on, cool. It?s must have a lot of power to drive the K340s. Can?t wait to read your impressions. If you are considering a wood accent faceplate that would look sweet. And as for the light, green or even amber to match the glowing tubes. Enjoy your new amp!

[philodox]

13 tubes, five of which have those white caps on top.

Those five tubes are pentodes, and the white cap is to cover the anode [a metal piece at the top]. I believe the wire runs off to ground the tube.

Those metal disc plates that surround each tube with holes drilled all around. I?ve never seen anything like it before.

I actually ordered those from an online dealer VT4C. The holes are not drilled through the chassis right now, though I think I may in the future for better ventilation. Right now it is just for the look.

It?s pretty awesome looking with a straightforward scientific flare to it. I like that you have to turn the key to turn it on, cool.

Yeah, too bad the switch failed.

Maybe I can find a more rugged key start switch to replace it with at some point. For now the amp is powered off by unplugging the power cord.

It?s must have a lot of power to drive the K340s. Can?t wait to read your impressions.

I'm not going to post impressions for a little while, but it can definately drive the K340's... I'll say that much.

If you are considering a wood accent faceplate that would look sweet. And as for the light, green or even amber to match the glowing tubes.

I'm thinking amber is the best match as well, though it depends on what swt61 cooks up for the faceplate.

Enjoy your new amp!

Thanks man, you enjoy those new headphones of yours. Lucky bastard.

[n_maher]

Congrats Jay, I hope it turns out sounding better than expectations! And I'm with you on the face plate, I've always kind of thought that the McAlister stuff deserved a bit nicer looking face plate. It's not that they look bad, just kind of bland in my book.

Happy listening!

[bhd812]

Congrats Jay, I like the old school look to her also..like an old micn amp.

Would love to hear it some day..hopfully

[alfie]

My first post here, just to say congrats for your beautiful Klingon amp

[deepak]

Congrats, I think the gold faceplates look really tacky. Silver suits the amps much better.

Do you know if Peter would be willing to do a black one?

[ojnihs]

dddddaaaaammmmnnnn

[KenW]

Very nice! Always a treat to get new gear especially of that caliber!

[philodox]

Thanks guys, I love it.

Congrats, I think the gold faceplates look really tacky. Silver suits the amps much better.

Do you know if Peter would be willing to do a black one?

Well, in the end, I think it will be replaced with a wood faceplate... but I do prefer silver to gold. As for black, it would be as simple as not putting a faceplate on... not sure how he would do the lettering though. Perhaps letraset with some clearcoat overtop?

[Chrysanthemum]

Nice amp. Looks way too tempting a buy.

[aerius]

I say you should get the capacitors painted in bling shiny gold. Or you could go the low key approach and paint them gloss black to match the rest of the amp.

BTW, pentodes are 27GB5's, which are single pentodes, and the top cap is for the 200V or whatever the plate voltage is.

[tkam]

Looks like I'll be joining the "my amp finally came in" crowd sometime next week. I spoke with Mikhail today and the final tube config is as follows: 2 x 6sn7 (or 6414 w/ adapters) --> 2 x 6bl7 --> 2 x 6528. The amp should drive the hell out of any headphone and make a nice pre-amp as well

[philodox]

BTW, pentodes are 27GB5's, which are single pentodes, and the top cap is for the 200V or whatever the plate voltage is.

Yeah, Kevin already PM'ed me about that. I guess Peter decided to not go with dual pentodes.

[KenW]

Looks like I'll be joining the "my amp finally came in" crowd sometime next week. I spoke with Mikhail today and the final tube config is as follows: 2 x 6sn7 (or 6414 w/ adapters) --> 2 x 6bl7 --> 2 x 6528. The amp should drive the hell out of any headphone and make a nice pre-amp as well

Nice! I've got the 6414 leading the 6bl7's right now. Great combo. He'd sent me a set of the 6414's to try and I was busy with all the other tubes on hand so they just sat there. Recently, I was looking through my tube case and saw those sitting there and it reminded me that I hadn't tried them yet. Popped them in and began to kick myself for not trying them sooner!! You'll love 'em!

[philodox]

Looks like I'll be joining the "my amp finally came in" crowd sometime next week. I spoke with Mikhail today and the final tube config is as follows: 2 x 6sn7 (or 6414 w/ adapters) --> 2 x 6bl7 --> 2 x 6528.

So three stages? Cool, can't wait to see it. Is it a PPX variant, or MPX, or something new entirely?

The amp should drive the hell out of any headphone and make a nice pre-amp as well...

That just about describes my amp as well, though the jury is still out on Grados.

[philodox]

Something strange has happened... all of a sudden I like classical music.

[ojnihs]

Something strange has happened... all of a sudden I like classical music.

[tkam]

So three stages? Cool, can't wait to see it. Is it a PPX variant, or MPX, or something new entirely?That just about describes my amp as well, though the jury is still out on Grados.

Yep two gain stages and the output stage. To the best of my knowledge it's a new design. Yeah it'll easily drive anything, plenty of current and an output impedance of around 2 ohms should make it a great match with low imp. phones. The 6528 is a beast of a tube each one requires 5A of heater current, so the power supply should be rather impressive as well.

[philodox]

That output impedance is nice and low... This is also a good thing for high impedance headphones as well. I think my amp has an output impedance of 40 ohms or so.

[tkam]

That 40 ohm output impedance could very well explain any issues you were having Grados

[justin]

That 40 ohm output impedance could very well explain any issues you were having Grados

I doubt it. 40 ohms is a low output impedance for an OTL tube amp. Most of the amps I have seen have a real output impedance between 100 and 300 ohms.

Almost nobody gives out the real specs.

[philodox]

I doubt it. 40 ohms is a low output impedance for an OTL tube amp. Most of the amps I have seen have a real output impedance between 100 and 300 ohms.

I doubt Peter would lie to me. Is there an easy way to measure it?

EDIT: Just re-read your post and I think I took it the wrong way [and missed tkams post]. You just meant that you doubt 40 ohms output impedance would be a problem with Grados?

[justin]

There are ways to approximate it but without the right equipment it will be difficult. What are the tubes and what is the circuit topology? I was just saying that based on output impedance alone, I don't think you will have a problem with 40 ohms and Grados. Plenty of people use their Grados with high output impedance amps and while this is going to change the sound nobody really reports on any "problems" with it. I'm not aware of any commercially sold OTL headphone amp with a Zo less than 40.

Here is the Atmasphere MA-1 MkIII. http://www.atma-sphere.com/products/ma1.html

It took 14 6AS7 output tubes per channel to get the output impedance down to 2.3 ohms. They are dual triodes so that's 28 triodes. As a cathode follower 1/2 6AS7, a popular configuration in a headphone amp, will have an output impedance of about 100 ohms. The output impedance will cut in half each time the tubes are doubled. So, I'm coming up with about 3.5 ohm output impedance for 14 tubes. They probably have some negative feedback that is bringing it down a bit more. I'm sure there is someone who can correct this if I'm wrong.

[aerius]

Yep two gain stages and the output stage. To the best of my knowledge it's a new design. Yeah it'll easily drive anything, plenty of current and an output impedance of around 2 ohms should make it a great match with low imp. phones. The 6528 is a beast of a tube each one requires 5A of heater current, so the power supply should be rather impressive as well.

You know what would be really funny? If someone built a headphone amp using a GM100 tube.

I wonder if KG is secretly working on the plans for one...