Novar Spud :: A $200 sweep tube Spud with PCB

[wcakey]

Nevermind

DUH... nevermind. I just realized that I misread the instructions. I thought you said to measure between pins 6 and 8 (which doesn't make sense), but you said measure the voltage "at" pins 6 and 8 of TU1 and TU2.


All is well. The amp is working. Still have to hook it up to my regular speakers, but sounded very promising on my tiny test speakers.


Thanks

 

[tomchr]

I somehow missed the posts above. Sorry about that. I'm glad you got the amp working.

Tom

 

[wcakey]

No worries. Not only did I get it working but I have been enjoying it very much over this Thanksgiving week.

I chose to go the 6GF7(A) route. With an Alps volume control in front, I find I need to turn it up well past half way to get into the desired listening range even with my 98 db efficiency speakers. That's using a laptop as the input source. I have not checked it out with a CD player as source: it might be louder that way.

However, despite the need to turn it up, the sound quality is excellent; highly detailed and with a lot more bass than I was expecting.

 

[tomchr]

I like the 6GF7A. That and the 6LR8 in triode mode are my favourites in that amp.

There's no harm in having to turn the volume knob.

Tom

 

[tomchr]

Just an FYI: I will be focusing on my solid-state amplifier designs going forward. Thus, the Novar Spud will be discontinued once the current stack of boards has sold. I have seven boards left in the stack. You can find them here: Novar Spud | Neurochrome :: Audio

It's a neat little amp. I've come to like the sweep tubes. Get the board while you can.

Tom

 

[tgreese]

This is a lovely little board. Waiting on my output transformers.



Tom, how do you make the fancy lead bends?

 

[tomchr]

I bend the lead over a pair of regular needle nose pliers to form two hard 90º bends. I then use round nose pliers to make the U shape. Switch back to needle nose for the 90º exit from the U. After a bit of practice, the process goes pretty quickly. It keeps the hot resistors off the PCB and looks pretty.

Tom

 

[tgreese]

Maybe lovely was the wrong word. It's a very professional-looking board, reflecting a lot of thought in development and design. Additionally, Tom makes sourcing the parts and assembling the board easy with click-to-fill BOMs from Mouser and plenty of discussion. Maybe too easy for this audience? It will be interesting to see how this turns out.

 

[Moderation Team]

Thread moved to Vendor's Bazaar.

 

[tomchr]

Fair enough. This thread was started before or around the time I started my business, so by now it certainly belongs in the Vendor's Bazaar.

Thanks,

Tom

 

[tomchr]

Two boards left. Once they're gone, I will discontinue the Novar Spud. It's a great little amp, but I'd rather focus my efforts on my solid state circuits as that will be my focus going forward.

Tom

 

[lavane]

There were three. I ordered one earlier.

 

[tomchr]

Yep. I just packed up your order. Thank you. It'll be underway by Monday morning and should arrive in 1.5-2 weeks.

Now down to one (1) board.

Tom

 

[tomchr]

And the last board has just sold. The Novar Spud is now officially retired.

Thank you to all who bought boards or otherwise supported this project. I greatly appreciate it. Best of luck with your builds.

Tom

 

[pelayostyle]

The Novar Spud might be retired but its not dead. All this extra time I've had at home lately has given me a chance to finally complete old projects that were put on the back burner. Decided to finish up the Novar Spud I bought years ago. Used some scrap plywood for the skirt and a piece of 1/8" aluminum for the top.

Setup with 6LR8's in triode mode with GXSE15-5K output trannys. So far I've used it with some Okapi's with Mark Audio 7MS drivers and it sounds fantastic.

 

[dolphin123]

Who wants?

An externally hosted image should be here but it was not working when we last tested it.

Still I have a few boards if needed.

 

[cbueche]

Tom, I only now came on your circuit by luck. I understand your decision to stop selling boards, but would you consider releasing your work under some public-domain license ? Or to someone here doing a group-buy ?

 

[poseidonsvoice]

Tom, I only now came on your circuit by luck. I understand your decision to stop selling boards, but would you consider releasing your work under some public-domain license ? Or to someone here doing a group-buy ?

You can easily PTP wire this circuit from the 1st post of this thread and post #30.

Best,
Anand.

 

[tomchr]

Tom, I only now came on your circuit by luck. I understand your decision to stop selling boards, but would you consider releasing your work under some public-domain license ? Or to someone here doing a group-buy ?

Sorry. I seem to have missed your post.

I do not give out the full schematics.

If someone is willing to organize a group buy, I'll be happy to provide them with the design doc and ship them PCBs. The group buy organizer would be responsible for handling the support (i.e. answer the questions related to transformers, where to get sockets, finding substitutes for out-of-stock parts, etc.)
I would provide a nice bulk discount to the organizer. Whether they choose to pocket the discount or distribute it in the form of lower prices will be up to them. I would need an order of at least 20 boards. More is better (and would result in a better bulk discount for the group buy organizer).

If you're interested in organizing a group buy, please contact me by email (use the Contact form on my website) or PM.

Tom

 

[cbueche]

Anand and Tom, thx for your answers. I will probably build a ptp version and if happy with it come back to Tom to organize something. The sailing season is starting soon so it will be in months, if any.