See 6P45S PPP Monoblocks. for the latest schematics.
So I've decided to cannibalise some of my other amps that collect dust to build 2 6P45S monoblocks.
Triode connection. B+=290V-320V. Idle 120mA/tube. Load=650R or 1300R EDIT: 2600R
Basically, I'm thinking of building the amp I have with both channels in parallel. In PPCalc:
With a 1300RLa-a, I get 22.5W class A, 119W total.
What do you think? This entire project will only cost me the price of the chassis.
R1-R4 = 10R. R5-R8 1k = R9-R12 = 220k
The OPT will be made of two Triad VPT18-13800 in parallel. (500VA)
170W from "triodes" for less than the price of 30W from a pair of 300B
Hot tip: Heater cord works well for top caps. 300V rated (so good to much higher than that in practice) and 105c rated, too.
So I've decided to cannibalise some of my other amps that collect dust to build 2 6P45S monoblocks.
Triode connection. B+=290V-320V. Idle 120mA/tube. Load=650R or 1300R EDIT: 2600R
Basically, I'm thinking of building the amp I have with both channels in parallel. In PPCalc:
With a 1300RLa-a, I get 22.5W class A, 119W total.
What do you think? This entire project will only cost me the price of the chassis.
R1-R4 = 10R. R5-R8 1k = R9-R12 = 220k
The OPT will be made of two Triad VPT18-13800 in parallel. (500VA)
170W from "triodes" for less than the price of 30W from a pair of 300B
Hot tip: Heater cord works well for top caps. 300V rated (so good to much higher than that in practice) and 105c rated, too.
Attachments
Last edited:
Voila.
This is as it's built now, but I've used one of these for it, too. 500W 12VDC transfer 18VAC & 0-220v-380v inverter module | eBay
Well I finished them. Here's a pic of one of the second one.
So right now, I'm using 6A10 diodes for the heater supply. I get only 11.4V loaded which is -10% of the rated voltage. I found the SM74611 diode with a forward drop of only 26mV @ 8A, but there are surface mount.
Any reason I can't just dead bug them?
This is as it's built now, but I've used one of these for it, too. 500W 12VDC transfer 18VAC & 0-220v-380v inverter module | eBay
Well I finished them. Here's a pic of one of the second one.
So right now, I'm using 6A10 diodes for the heater supply. I get only 11.4V loaded which is -10% of the rated voltage. I found the SM74611 diode with a forward drop of only 26mV @ 8A, but there are surface mount.
Any reason I can't just dead bug them?
Attachments
My stupendous uses 16 6P1P tubes... Biased with bypassed LM317 in the cathode leg.
3 years ago I planned to make such an amp.
But did not dare to start.
TONY TECSON
16 KT88 how did you bias them?
Most i have used is 4 KT88 triode fixed bias
fixed bias, the tubes are well matched to begin with..
8 bottles per channel, 4 tubes per side..
3 years ago I planned to make such an amp.
But did not dare to start.
You may be interested in another thread of mine: The Stupendous 6P1P 4PP amplifier!
You've probably seen it though.
I thought I'd share the final design schematics.
Phase splitter is powered by one of these set to max voltage. DC-DC 8-32V to 45V-390V Step-up Module ZVS High Voltage Capacitor Charge Board | eBay
gNFB (not shown) is 1000R || 330pF
They are biased by these: Module AB-4 for 4 tubes, PP & PPP amps, requires 6.3VAC & bias supply from the amps circuit, with TTL error signal output. TES
Phase splitter is powered by one of these set to max voltage. DC-DC 8-32V to 45V-390V Step-up Module ZVS High Voltage Capacitor Charge Board | eBay
gNFB (not shown) is 1000R || 330pF
They are biased by these: Module AB-4 for 4 tubes, PP & PPP amps, requires 6.3VAC & bias supply from the amps circuit, with TTL error signal output. TES
Attachments
Last edited:
I thought I'd share the final design schematics.
Phase splitter is powered by one of these set to max voltage. DC-DC 8-32V to 45V-390V Step-up Module ZVS High Voltage Capacitor Charge Board | eBay
gNFB (not shown) is 1000R || 330pF
They are biased by these: Module AB-4 for 4 tubes, PP & PPP amps, requires 6.3VAC & bias supply from the amps circuit, with TTL error signal output. TES
What do these four 51k resistors R2, R10, R11, R12 do?
Best regards!
Those resistors are duplicated in both drawings, and should connect to the -V bias lines instead of ground. As shown, the phase splitter can be used with a cathode biased output stage, and they can be omitted if using the output stage shown in the schematic.
Yes there are a couple of pretty good fishing holes for surplus in Toronto.
"I got them surplus for $6 CAD each." That's a good price, is there a good place near you for surplus? All the old surplus places here in the UK have long since closed down, there may be on or two left but nothing like there used to be.
A.
Yes there are a couple of pretty good fishing holes for surplus in Toronto.
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