[nikongod]

Many many thanks nate for posting up the PSU schematic. I am happy to see that an OTL tube amp that sounds as pimptastic as the reviews indicate can be built with such small value caps. You are an inspiration.

 

[mrarroyo]

Man, if I only had skills!

Thanks for posting the diagrams.

 

[holland]

Thanks for posting the details. This looks surprisingly easy to build, making it that much more accessible.

It's too bad I blew my budget already or I'd move this up to #1 ahead of all my other half built stuff.

 

[n_maher]

Quote:

Originally Posted by holland /img/forum/go_quote.gif Thanks for posting the details. This looks surprisingly easy to build, making it that much more accessible. It's too bad I blew my budget already or I'd move this up to #1 ahead of all my other half built stuff.

Just remember that schematics can be deceptive and that the devil is in the details. Casework on this project not only requires a fair amount of time but tools as well. Assuming one were to use the same caps that I did you'd need to have a drill press and several different sizes of hole saws. I'd say I spent well over $100 just on tools to complete this build and the fasteners weren't cheap either. The raw parts cost that you'd get by looking at the schematic really only hints at the total build cost. All the same I'm working on a BOM with sources and prices, not sure when I'll get it done or posted though.

 

[cetoole]

Quote:

Originally Posted by n_maher /img/forum/go_quote.gif All the same I'm working on a BOM with sources and prices, not sure when I'll get it done or posted though.

Just dont let the wife see it!

 

[holland]

Quote:

Originally Posted by n_maher /img/forum/go_quote.gif Just remember that schematics can be deceptive and that the devil is in the details. Casework on this project not only requires a fair amount of time but tools as well. Assuming one were to use the same caps that I did you'd need to have a drill press and several different sizes of hole saws. I'd say I spent well over $100 just on tools to complete this build and the fasteners weren't cheap either. The raw parts cost that you'd get by looking at the schematic really only hints at the total build cost. All the same I'm working on a BOM with sources and prices, not sure when I'll get it done or posted though.

I absolutely agree with that, and the prices can vary wildly with it. I've done enough stuff in various hobbies to have seen that (guys can spend thousands of dollars on beautification alone).

I think there are many alternatives to doing things, it's just a matter of how creative you want to be or how pretty you want to make it. Fortunately, I'm one of function over form and I'm not afraid to deviate from what amp builder XYZ uses. I'm also not one to show things externally, nor do I showcase, so that makes being cheap easy, but a 3RU or 4RU case may be necessary for this thing for internal mounting. That's $$$ by itself as well.

I saw in a little dot thread that cut up soup cans painted black can be used as cap covers.

 

[digger945]

Is there anything all that special about the trafo's used, e-core/toroid and if I find a good buy on a trafo (surplus or used) that is rated for 110v and I happen to have say 125v at the wall socket, on a 3 to 1 winding that would equate to 45v difference.
Just wondering if and how you deal with that. I'm doin my own research, just thought I would get the ideas of experienced amp builders first.
Thanks

 

[jamess71]

Looks sweet Nate. Excellent casework. When are we gonna have another meet so I can hear it?

 

[n_maher]

Quote:

Originally Posted by digger945 /img/forum/go_quote.gif Is there anything all that special about the trafo's used

The special thing from where I sit is that this amp requires a lot of current capacity (relative to other tube amps) on the HV winding. It takes a huge trafo to do that and it's not something you're likely to come across unless you're hunting in some pretty odd salvage yards. When Pete and I were looking for possible candidates there weren't many in the "affordable" bracket and the BFT isn't exactly cheap.

And thanks James - Salty, drp and I have talked about something this fall maybe. But life is pretty complicated for all of us right now so it's been tough to try and pull anything together. But if there's a meet, I'll try and make it and schlep my 60lb boat anchor with me.

 

[tosehee]

Nice looking amp.

A few questions..

1. Where does this stand in terms of competitors like WA22, EC SE, DNA Sonnett, WA5LE, Bijou and such?
2. I've never done any DIY in the past. How much would it cost to buildl this if commissioned to a builder?

 

[n_maher]

Ok, time to update this thread and have some more fun in the process.

Earlier in the year I sold The Menace. Sad day, for sure, but one that ultimately became more and more necessary as my daughter started to take over more and more of the space that I formerly called audio-home. As I found myself now headphone ampless I started digging through drawers in my diy workshop looking to see if I had enough parts to build a power supply for my long out of service Millett Hybrid. What I found was that in typical fashion I'd acquired an insane degree of spare parts for the Menace. So with a little help from my friend nikongod we tweaked an existing design that used the same tube compliment but had a transformer coupled output and created what I named the MenaceTC Lite. Why Lite? Well, two reasons, one it weighs less than the original Menace due largely to the fact that it uses a SS power supply and two, the real MenaceTC is still sitting in 4 more boxes and is my "keep me sane this winter" project.

So while this amp won't take up permanent residence it seemed like a great warm-up for the bigger project and a good way to reduce the clutter.

When I get a chance I'll try to finish up the Lite schematic and post it, it's a deceptively simple looking beast but is not without it's share of neat tricks and takes some careful attention to details to get it quite. Some highlights: a choke filtered power supply rather than the typical throw a huge cap in there style, it uses LEDs to bias the input tube along with some other trickery that Ari will have to explain involving some CCS's. But this is getting long, so without further adieu here she is in mostly finished garb. Some folks got a chance to hear this at the most recent NYC meet and the comments were mostly positive.


Top Side

Wiring Overall

Custom Top Panel (by Cam-Expert)

Back Panel (prior to trafo cover)

 

[TimJo]

Wow, looks great Nate.

Hats off to you and Ari. What kind of transistors are you using on those CCS's?

 

[Skylab]

Very cool! That seems like an amp that would have a lot of appeal - not everyone can handle a full Menace

 

[n_maher]

Quote:

Originally Posted by TimJo /img/forum/go_quote.gif Wow, looks great Nate. Hats off to you and Ari. What kind of transistors are you using on those CCS's?

10M45s and thanks, it came together better than I could have hoped really. I should also mention that cetoole helped me with some final wiring tweaks that really pushed the noise floor amazingly low. I've tried the amp with my Ety ER4Ps, there is some background noise but it's lower than the noise floor of most recordings and disappears once there is actual music playing. With any full-sized can that I've tried (both open and closed) I have to unplug the headphone jack to be sure that there's any noise.

Quote:

Originally Posted by Skylab /img/forum/go_quote.gif Very cool! That seems like an amp that would have a lot of appeal - not everyone can handle a full Menace

Thanks man, while it weighs less and is less bulky compared to the original it's still rather beastly. I'd guess around 25lbs total so it seems I don't know how to build portables anymore.

 

[Skylab]

Quote:

Originally Posted by n_maher /img/forum/go_quote.gif Thanks man, while it weighs less and is less bulky compared to the original it's still rather beastly. I'd guess around 25lbs total so it seems I don't know how to build portables anymore.

Well, good iron does carry some weight