[Juaquin]

No kidding - for those who are ordering kits, wait 'till you get the package. I'd almost go so far as to say that TomB is obsessive-compulsive the way he packs those things

 

[burgunder]

Quote:

Originally Posted by the_equalizer /img/forum/go_quote.gif Unfortunately I don't think such an adapter exists, even though I know there are adapters for some popular audio tubes (like this one, for example); so this 19J6 -> 12AU7 adapter would have to be custom built.

I seem to remember an article about DIY tube adapters, but I'm not able to locate it rigth now.

Edit. I found what I was looking for http://www.head-fi.org/forums/f5/rev...ifiers-301219/

 

[the_equalizer]

Quote:

Originally Posted by burgunder /img/forum/go_quote.gif I seem to remember an article about DIY tube adapters, but I'm not able to locate it rigth now. Edit. I found what I was looking for http://www.head-fi.org/forums/f5/rev...ifiers-301219/

Very interesting ! I read the whole article and followed the links to leedselect.com. Apparently they have the necesary items in stock

7 pin minature plug -fits sockets for 1L6, 6AU6 etc
good for making tube adapters and test jigs with
screw on back shell - NOS $7.00

Add a couple of regular ceramic 9-pin tube sockets and copper pipe caps.

Then use a DPDT mini to switch to a couple of 170Kohms resistors in series with R2/R8 and you'd have a SSMH that could roll with either 19J6 or 12A_7 tubes

.

cheers !

 

[UKToecutter]

Quote:

Originally Posted by Juaquin /img/forum/go_quote.gif No kidding - for those who are ordering kits, wait 'till you get the package. I'd almost go so far as to say that TomB is obsessive-compulsive the way he packs those things

Great,

There was me thinking I was the only guy on the forum with OCD!!!!

 

[Yaka]

Quote:

Originally Posted by Juaquin /img/forum/go_quote.gif No kidding - for those who are ordering kits, wait 'till you get the package. I'd almost go so far as to say that TomB is obsessive-compulsive the way he packs those things

well im glad he takes the time to do that, there have times in the past when ive oardered parts from farnell, mouser etc that they had been dammaged and rendered un usable do to poor packaging. one of many reasons i am about to order a mini max kit as my next proj

 

[loki993]

Om so Ive been thinking about tacking one of these for some time. I have a few questions. First off are there any tweaks? Possibly higher end parts, Id like the get the best sounding Amp I can, within reason. If the headphones I'm using make a difference I would be using it with some AD700s a bit, but it will be used primarily to try and clean up my DT770 pros. Love the phones, love the bass, but as we all know the highs are a bit muddy.

Has anyone done any tube rolling or is that not really possible due to the way the tubes are set up?

Also Ive heard about someone selling kits. What are these running and how would I go about getting one If I wanted?

Thanks.

 

[Juaquin]

The "tweaks", besides doing obvious replacements (extremely high-end caps in place of the regular ones, etc) is to build one of the other Millet's, like the MiniMax. Similar topology (hybrid) with more bells and whistles.

Tube rolling is not possible the standard way these are built. It is possible to use 12AU7 tubes, but it requires changing some resistors and a different socket, so it's not so much rolling as it is rebuilding. A couple posts up, Equalizer mentions some socket adapter information that would make switching back and forth easier, although I still wouldn't call it rolling.

If you read two pages back, you'll see the kits will be going for $120 and they'll be available at Beezar Audio on Friday night.

 

[the_equalizer]

Quote:

Originally Posted by Juaquin /img/forum/go_quote.gif The "tweaks", besides doing obvious replacements (extremely high-end caps in place of the regular ones, etc) is to build one of the other Millet's, like the MiniMax. Similar topology (hybrid) with more bells and whistles. Tube rolling is not possible the standard way these are built. It is possible to use 12AU7 tubes, but it requires changing some resistors and a different socket, so it's not so much rolling as it is rebuilding. A couple posts up, Equalizer mentions some socket adapter information that would make switching back and forth easier, although I still wouldn't call it rolling. If you read two pages back, you'll see the kits will be going for $120 and they'll be available at Beezar Audio on Friday night.

Actually you can roll tubes with a 12A_7 version. Personally I have tried new production JJ brand 12AU7 tubes, new production Electro-Harmonix 12AX7 tubes and new production 12AX7 Mullard tubes.

A friend who also built a 12A_7 version also tried 12AT7 tubes (a pair of old, used ones he found in a scrap shop) and I'm pretty sure he also plugged a couple 12AV7's

They all work great without needing any further modification to the circuit aside from the "one resistor change" as compared to the 19J6 version.

cheers!

 

[Juaquin]

Ah, so you can roll with a resistor change? Good to know. Still not quite plug-and-play, but with creativeness (a DPDT switch mounted to the case, as you suggested) you could make it pretty simple.

 

[the_equalizer]

Quote:

Originally Posted by Juaquin /img/forum/go_quote.gif Ah, so you can roll with a resistor change? Good to know. Still not quite plug-and-play, but with creativeness (a DPDT switch mounted to the case, as you suggested) you could make it pretty simple.

I think I need to clarify what I wrote above

If you build a 12A_7 version, you can roll tubes within the 12A_7 family, that is 12AT7, 12AU7, 12AV7 and 12AX7 tubes.

As you very well mentioned in your previous post, a 12A_7 version differs from the 19J6 version in two ways:

Electrically: you need to change R2 and R8 to be 390 Khoms
Mechanically: you need to use 9-pin sockets for the tubes (as opposed to the 7-pin socket used by the 19J6)

So once you change that socket, plugging in a 19J6 is no longer possible... (unless you use adapter sockets

)

cheers!

 

[loki993]

Quote:

Originally Posted by Juaquin /img/forum/go_quote.gif The "tweaks", besides doing obvious replacements (extremely high-end caps in place of the regular ones, etc) is to build one of the other Millet's, like the MiniMax. Similar topology (hybrid) with more bells and whistles. Tube rolling is not possible the standard way these are built. It is possible to use 12AU7 tubes, but it requires changing some resistors and a different socket, so it's not so much rolling as it is rebuilding. A couple posts up, Equalizer mentions some socket adapter information that would make switching back and forth easier, although I still wouldn't call it rolling. If you read two pages back, you'll see the kits will be going for $120 and they'll be available at Beezar Audio on Friday night.

Missed that, was just on here a couple days go and they still didn't know when they were coming. Good to know.

Wow, that's a lot more than the original $50 when I first saw this. I suppose the PCB and the Custom enclosure are a bit of the cause of that price though. Is he using better components that the original design?

What do the MiniMax kits run? They are out of stock on the website.

Can the SSMH still be done for under or around $50? I kinda have gravitated towards this particular amp, because it seemed to be simple to build, it would be my first, and was really cheap. Even cheaper, by a fair bit, than a lot of solid state amps I was looking at. Have prices gone up that much?

 

[loki993]

Quote:

Originally Posted by the_equalizer /img/forum/go_quote.gif I think I need to clarify what I wrote above If you build a 12A_7 version, you can roll tubes within the 12A_7 family, that is 12AT7, 12AU7, 12AV7 and 12AX7 tubes. As you very well mentioned in your previous post, a 12A_7 version differs from the 19J6 version in two ways: Electrically: you need to change R2 and R8 to be 390 Khoms Mechanically: you need to use 9-pin sockets for the tubes (as opposed to the 7-pin socket used by the 19J6) So once you change that socket, plugging in a 19J6 is no longer possible... (unless you use adapter sockets ) cheers!

Is this a recommended setup? How do they sound compared to the 19J6. What little Ive been reading in the past few days, Haven't been on the site in a while, is seems that the 19J6s are getting hard to find. True?

 

[loki993]

Ok Ive been looking around the Minimax Kits seem the be over $200, definitely not an option for me right now.

 

[the_equalizer]

Quote:

Originally Posted by loki993 /img/forum/go_quote.gif Is this a recommended setup? How do they sound compared to the 19J6. What little Ive been reading in the past few days, Haven't been on the site in a while, is seems that the 19J6s are getting hard to find. True?

Yup 19J6 are currently scarce, though some recent posts mentioned they're available at some sites at $10 US per tube, which is still cheaper than new current production 12AU/X/T7 tubes.

I wouldn't call it a 'recommended setup' It's just another option at your disposal to build the amp. The sound is slightly less warm than the 19J6, somewhat more edgy, but that's only my perception.

If you search the thread for 12SR7 you'll find there's a third option using cheap and easy to find 12SR7 tubes. I haven't built or heard that version so I can't comment, but those who've built it like it.

You can certainly build this amp for less than $50.00 but you'll obviously have to forego the kit. Get the PSU from e-bay, get the tubes from a tube supplier, be creative for the enclosure, etc..

Having said that, the Beezar.com kit is seriously worth it. An outstanding value in all respects: boutique output capacitors, 1% metal film resistors, WIMA film caps, a pre-drilled extruded aluminum enclosure... Having built one, I can say that the results are so professional looking that I could barely believe I had put the thing together myself.

cheers!

 

[loki993]

Quote:

Originally Posted by the_equalizer /img/forum/go_quote.gif Yup 19J6 are currently scarce, though some recent posts mentioned they're available at some sites at $10 US per tube, which is still cheaper than new current production 12AU/X/T7 tubes. I wouldn't call it a 'recommended setup' It's just another option at your disposal to build the amp. The sound is slightly less warm than the 19J6, somewhat more edgy, but that's only my perception. If you search the thread for 12SR7 you'll find there's a third option using cheap and easy to find 12SR7 tubes. I haven't built or heard that version so I can't comment, but those who've built it like it. You can certainly build this amp for less than $50.00 but you'll obviously have to forego the kit. Get the PSU from e-bay, get the tubes from a tube supplier, be creative for the enclosure, etc.. Having said that, the Beezar.com kit is seriously worth it. An outstanding value in all respects: boutique output capacitors, 1% metal film resistors, WIMA film caps, a pre-drilled extruded aluminum enclosure... Having built one, I can say that the results are so professional looking that I could barely believe I had put the thing together myself. cheers!

Ok so it is High end stuff, that would explain the higher price. Id love to try one, I just don't have that money right now and I doubt they will last very long.