[Tachikoma]

Hi, I'm going to have this amp http://gilmore.chem.northwestern.edu/head3.htm built for me soon-ish and there are a few things about the schematic that me and my builder would like to know, since I know next to nothing about electronics and he's new to tube amplifiers >_>

Firstly, what exactly are the A B C and Ds in the schematic for? and secondly, the schematic is supposed to show both channels, but why is there only one set of inputs?

Will be very grateful for any help >_<

 

[spritzer]

Sorry about the confusion but the schematic is for a single channel only. Must not answer PM's half awake...

The letters stand for connections that would have messed up the schematic had they been drawn on it.

The KGBH psu should fit like a glove and it's up to you how you handle the filaments, AC or DC.

 

[luvdunhill]

heh 12 0a2 tubes, that's going to look sweet with all the glow tubes!

 

[Tachikoma]

Chances are I won't have the OA2s in my build... for now at least. Too much trouble to implement correctly.

 

[spritzer]

Quote:

Originally Posted by luvdunhill /img/forum/go_quote.gif heh 12 0a2 tubes, that's going to look sweet with all the glow tubes!

I've already stocked up on them. Next time I order some parts I'll get the rest for this amp and try it out.

Quote:

Originally Posted by Tachikoma /img/forum/go_quote.gif Chances are I won't have the OA2s in my build... for now at least. Too much trouble to implement correctly.

Just please don't use zeners. They are bad enough in the power supply...

The 0A2's shouldn't be tough to implement but they will require some extra metal work and 12 extra 7-pin sockets.

 

[justin w.]

I tried this and it didn't work, at least with my 0A2s. Spritzer, try getting some SG1Ps, I had wanted to try those but never did...check eBay.

 

[spritzer]

Thanks for the suggestion. I found them on the bay but they will cost me much more then the 02As did so I'll try 02A's first. I'll have to do this amp cheaply as my 845 based project is eating up a lot of money right now with even more to come. Transformers are really expensive when you need a lot of TOTL units...

 

[Tachikoma]

Quote:

Originally Posted by justin w. /img/forum/go_quote.gif I tried this and it didn't work, at least with my 0A2s. Spritzer, try getting some SG1Ps, I had wanted to try those but never did...check eBay.

Is there any advantage in using the SG1Ps?

Quote:

Just please don't use zeners. They are bad enough in the power supply...

Are there any good alternatives that won't involve 12 extra holes drilled into the chassis? <_<

 

[spritzer]

Quote:

Originally Posted by Tachikoma /img/forum/go_quote.gif Is there any advantage in using the SG1Ps?

I'm not quite sure. I'll have to look into it in the morning or Justin can save me the legwork.

Quote:

Originally Posted by Tachikoma /img/forum/go_quote.gif Are there any good alternatives that won't involve 12 extra holes drilled into the chassis? <_<

There are other ways but none are as cool. A good stepped drill is a necessity for any project like this and it will do those 12 extra holes with ease.

 

[luvdunhill]

Quote:

Originally Posted by spritzer /img/forum/go_quote.gif I'm not quite sure. I'll have to look into it in the morning or Justin can save me the legwork. There are other ways but none are as cool. A good stepped drill is a necessity for any project like this and it will do those 12 extra holes with ease.

if I had that many of the same size holes to make (yes, 24 tubes), I'd by a Greenlee punch for that specific tube size. The punchs are super cool and super easy to use.

 

[spritzer]

Quote:

Originally Posted by luvdunhill /img/forum/go_quote.gif if I had that many of the same size holes to make (yes, 24 tubes), I'd by a Greenlee punch for that specific tube size. The punchs are super cool and super easy to use.

The punches are a good alternative but stepped drills are simply better and faster. It really depends on the equipment you use with them though

 

[Tachikoma]

Quote:

There are other ways but none are as cool. A good stepped drill is a necessity for any project like this and it will do those 12 extra holes with ease.

Do tell, at the moment it seems that the zeners are destined to be in my signal path

We're going to commission a case builder for the casing... no need to buy stepped drills myself

One more thing...Since the unlabeled tubes on the schematic are supposed to be the "second half" of the 6H30s, aren't there only 10 tubes (including OA2s) per channel?

 

[Eokboy]

empire23 asked me to do the casework lol.

But I don't have any unibit. And you can't use it with Dremel iinm.

What kind of casing does your friend want to use?

 

[spritzer]

Quote:

Originally Posted by Tachikoma /img/forum/go_quote.gif Do tell, at the moment it seems that the zeners are destined to be in my signal path

Sorry for the late reply. As Kevin said in the comments about the schematic you can also use NE-2's which are neon bulbs that light up at 90v. Smaller then the 0A2's.

Quote:

Originally Posted by Tachikoma /img/forum/go_quote.gif We're going to commission a case builder for the casing... no need to buy stepped drills myself

Half the fun is building the case and the greatest source for any major and minor injuries...

Quote:

Originally Posted by Tachikoma /img/forum/go_quote.gif One more thing...Since the unlabeled tubes on the schematic are supposed to be the "second half" of the 6H30s, aren't there only 10 tubes (including OA2s) per channel?

There are 10 tubes per channel, six 0A2's, two 6H30 and two 6S4's.

 

[Tachikoma]

Quote:

Originally Posted by Eokboy /img/forum/go_quote.gif empire23 asked me to do the casework lol. But I don't have any unibit. And you can't use it with Dremel iinm. What kind of casing does your friend want to use?

Erm, something that can withstand a little heat ie no plastic casings. I'm the one who wants the amp.. <_<

Quote:

Sorry for the late reply. As Kevin said in the comments about the schematic you can also use NE-2's which are neon bulbs that light up at 90v. Smaller then the 0A2's.

This one sounds cool but I remember KG rubbishing the idea in the older DC electrostatic amp thread