Sir.Byrd's Push-Pull 6V6GTA tube build
- Thread starter Sir.Byrd
- Start date
Sir.Byrd
Lunatic Member
Partsconnexion, they were $1 a pop, silver plated contacts. You just have to epoxy them in place since there are no other provisions for mounting.
They are in the bargain basement section, but they appear to be the same as the Connex terminal strips, in case the discount ones go out of stock.
Thanks, the poplar was really cheap too, just pick a good board and it's the same price as the plain stuff.
1978_DREAMER
Active Member
I know this is a little off topic, but does poplar or tulip trees grow around Seattle? I've got 7 good size tulips growing in the yard that we planted as seedlings about 30 years ago. As a high schooler I used poplar to build my first stereo cabinet, It was a horizontal design that let the receiver (marantz 2250) sit prominently high in the center with a TT lower to the right and a top load cassette lower to the left. Ah, school projects, old memories now. That's a good looking layout so far. Can't wait to see the wiring go together! Jerry
GuyK
Addicted Member
A number of varieties of poplar grow here, but I think all except Black Cottonwood are introduced, and I don't think are a common find at the local mills. I think most of the hardwoods available at lumberyards are shipped in from elsewhere.
Sir.Byrd
Lunatic Member
Figured out the over-voltage in the power supply today. It was 505V DC with no load at start up, so we dropped that to 430V max at start with some bucking transformers, then we will go from there with resistors in the filter circuit.
Also talked about the option of swapping in 6L6s and removing the resistors in the filter circuit to have a 20-22 watt amp.
Also talked about the option of swapping in 6L6s and removing the resistors in the filter circuit to have a 20-22 watt amp.
Doc Zinger
Well-Known Member
Nice work, if you don't get it done in time could you just take the F5 in instead?
Sir.Byrd
Lunatic Member
They seem to be proud. I am proud as well, but not too much, I'ven't finished it yet!
I sure hope so! I should have used zebrawood to match, but I'd go broke making a matching system, since it's about 8 times more expensive than the poplar.
I could, except I would have to convince them that I put the tube amp entirely inside of the F5, since it's too late to change projects!
thefragger
Certified Crazy.
Just make sure you get it back when the teacher is done 'marking' it... !
Nice work man :thmbsp:
Which OPTs are those? The Edcor 25 watt?
If so, a 6L6GB would work. It'd probably wind up a useful 18w or so per channel. Maybe more, but you'd probably start to lose useful bass above about 18 watts per channel or so...
Regards,
Gordon.
Sir.Byrd
Lunatic Member
Bass response does not matter.
Wow, great job you did there :thmbsp:
specialidiot
Break Glass, Smoke Lucky
I realize that's your current view, but will that system be in place "forever"? Why limit this amp's capability?
I agree with S. Since you are starting freash anyway, might as well build it for any and all situations. If you are like me, your current set up will not be the same in 2 years.
Sir.Byrd
Lunatic Member
Huzah!
It lives!
I have a very stout 10 WPC tube amp, that's ruler flat from at least 20hz-20kHZ (didn't measure above or below that) and the voltage is right on the target of 380 at the first step, 335 at the second, and I forget what the third step was at, but it's all within about ±5V which is pretty good.
I had to put in a different rectifier tube, and it works with a bucking transformer to get the voltage just right, and the rectifier takes a while to warm up so by the time it has turned on, so have the rest of the tubes and the power supply stays below 450V the whole time.
Anyway, I just need to make everything that was clipped in externally internal, and then button it up with the final set of tubes and should be good to go!
It lives!
I have a very stout 10 WPC tube amp, that's ruler flat from at least 20hz-20kHZ (didn't measure above or below that) and the voltage is right on the target of 380 at the first step, 335 at the second, and I forget what the third step was at, but it's all within about ±5V which is pretty good.
I had to put in a different rectifier tube, and it works with a bucking transformer to get the voltage just right, and the rectifier takes a while to warm up so by the time it has turned on, so have the rest of the tubes and the power supply stays below 450V the whole time.
Anyway, I just need to make everything that was clipped in externally internal, and then button it up with the final set of tubes and should be good to go!
Sir.Byrd
Lunatic Member
Nien. Not until I work again on saturday.