5F6A-M Bassman Micro

[davidjon_99]

Got all my parts in from AES and Mouser. Nice that Mouser is in the Fort Worth area. Even with ground shipping I get orders in one or two days max.

Will be off work tomorrow and plan to start putting the turrets in my board and mounting components.

[robrob]

Mouser ships quick. I'm in Tennessee and I usually get stuff in two days too. I'm looking forward to your build, please post pics and status updates.

[davidjon_99]

Mouser ships quick. I'm in Tennessee and I usually get stuff in two days too. I'm looking forward to your build, please post pics and status updates.

Will do. This will be my first scratch build...making the turret board and drilling holes in the chassis. Ought to be interesting.

Did you get my emails on the layout I sent you and the question about which wires to use on the output transformer?

I modified your DIY layout a bit for my build using the 5Y3. Just need another set of eyes to look at it to see if I missed anything. For the output transformer I'm thinking that we would use the orange (#2) and yellow (#4) secondary wires for 22.5K:8. Is that correct?

[robrob]

Yes, you are correct on the output transformer wires. I'll try to take a look at your layout tomorrow.

[davidjon_99]

Yes, you are correct on the output transformer wires. I'll try to take a look at your layout tomorrow.

Excellent! Thanks.

[kkregsg]

Rob, you're killin' me here! I thought I had a few projects planned out ahead, but seeing your minis has just thrown that list out the window. I really like the demos on these, and have a few friends who would love these for home use. Bravo, and thanks for sharing.

[musicamex]

First, thanks to Robrob and other members here for all of the great info posted for us all to use and learn from and this cool micro bassman design.
I am going to try to build one from my "bone pile" and have a suitable chassis, PT and choke and all other parts on hand but was wondering how to adapt a p-t291 OT that I have a few of (new).

https://www.tubesandmore.com/products/t ... output-8-w

I have lots of speakers and can provide a secondary impedance of 2, 4, 8 or 16 ohms. I am in Mexico and would have to wait until late Jan until my next trip north to buy the Hammond 125 series spec'd in the design. Plus I like to improvise and learn in the process. I also have several salvaged pp trannies that I have measured and marked the turns ratio of that might work. Any suggestions would be greatly appreciated.

Thanks in advance for the help! I am posting this elsewhere too in hope of ideas.

[sluckey]

This amp wants a 22,500Ω load reflected to the output tube plates. If you connect an 8Ω speaker to the p-t291 terminals C and 1 you will reflect an 18,000Ω load to the tubes. Not optimum but should be close enough. After all, with a "micro" amp you're not really interested in transferring maximum power. I'd use it if I were building a bone pile amp.

[martin manning]

And being a triode output, there is a bit more flexibility.