6P14P Push Pull Amplifier
Push pull amplifier 6P14P-EV, ready assembled for final adjustments
Classic topology, i am using paraphrase phase splitter
Push pull amplifier 6P14P-EV, ready assembled for final adjustments
Classic topology, i am using paraphrase phase splitter
Attachments
Glowing 813 heater regulator test
Today i tested the start up behaviour of the regulators with a real tube, 813 in this case. the regulator is set for 8A startup current. Its rock solid, i have had it operating for a few hours like this now.
Today i tested the start up behaviour of the regulators with a real tube, 813 in this case. the regulator is set for 8A startup current. Its rock solid, i have had it operating for a few hours like this now.
Attachments
Yes is clean, i like to build my products as clean as possible
All enclosures which i use are custom build locally by a friend
great amp!
I am collecting parts for a Tubelab Simple pp amp project. Have 6p14-EV laying around. Are you satisfied with the sound of the russian tubes? Great looking amp you have built! Love the color of the amp on the right side of the picture. Have build some el 84se painted with that green color. Why are "all amps" in "aluminium" and black ?
I am collecting parts for a Tubelab Simple pp amp project. Have 6p14-EV laying around. Are you satisfied with the sound of the russian tubes? Great looking amp you have built! Love the color of the amp on the right side of the picture. Have build some el 84se painted with that green color. Why are "all amps" in "aluminium" and black ?
Hi all,
Here is my latest amp, a stereo SE KT88. Top plate is 1/4” aluminum cut by laser, my friend and I exchanged of services.
I was curious about using a toroidal as an OPT, well the one from Toroidy in Poland works very well.
Since it’s DIY I added some switches on top.
BR
Eric
Here is my latest amp, a stereo SE KT88. Top plate is 1/4” aluminum cut by laser, my friend and I exchanged of services.
I was curious about using a toroidal as an OPT, well the one from Toroidy in Poland works very well.
Since it’s DIY I added some switches on top.
BR
Eric
Attachments
e_fortier,
That amp looks very nice!
And with the topside switches, it looks very good for tube rolling, and for easily comparing UL and Triode modes.
I do worry about a few things:
Only switch from UL to Triode mode, or Triode to UL mode when the amp is powered down, and the filaments are cold and B+ is discharged.
Switching the screen can create really nasty transients for tubes, output transformers, tweeters, and your ears.
Depending on whether the amp is Fixed Adjustable Bias or Self Bias, check to see if the total g1 DC return resistance does not exceed the specifications for the 6550 tubes (much lower resistance in fixed bias than self bias, and the 6550 g1 resistor specs are lower than just about any other popular output tube).
I always wanted to check out those Toroids from Poland.
There need to be B+ bleeder resistors; you may be changing tubes, but be sure the filaments are cold, and that B+ is discharged by the bleeders.
That amp looks very nice!
And with the topside switches, it looks very good for tube rolling, and for easily comparing UL and Triode modes.
I do worry about a few things:
Only switch from UL to Triode mode, or Triode to UL mode when the amp is powered down, and the filaments are cold and B+ is discharged.
Switching the screen can create really nasty transients for tubes, output transformers, tweeters, and your ears.
Depending on whether the amp is Fixed Adjustable Bias or Self Bias, check to see if the total g1 DC return resistance does not exceed the specifications for the 6550 tubes (much lower resistance in fixed bias than self bias, and the 6550 g1 resistor specs are lower than just about any other popular output tube).
I always wanted to check out those Toroids from Poland.
There need to be B+ bleeder resistors; you may be changing tubes, but be sure the filaments are cold, and that B+ is discharged by the bleeders.
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Wow, nice e_fortier! 6A3sUMMER, glad to hear you articulate about switching UL to triode. I considered building one amp that way but I was skittish about switching while fired up. I figured it wouldn't be good but hadn't gone to the trouble to think about it.
Thanks for the compliment guys.
I always power down the amp before switching between UL and Triode.
I can’t stand hum so I have the following;
-CLC Power Supply
-CCS on front end triodes
-DC elevated heaters
The amp is self bias but when changing from let’s say EL34 to KT88 there’s a few power resistors being put in parallel via the switch, I have about 70mA for EL34 and 100mA for KT88, B+ is 370Vdc. I also of course use a bleeder resistor of the B+
The bass was slightly sluggish regardless of the chosen mode therefore I added some Schade local feedback and now the bass is more controlled. Pink Floyd is delightful.
BR
Eric
I always power down the amp before switching between UL and Triode.
I can’t stand hum so I have the following;
-CLC Power Supply
-CCS on front end triodes
-DC elevated heaters
The amp is self bias but when changing from let’s say EL34 to KT88 there’s a few power resistors being put in parallel via the switch, I have about 70mA for EL34 and 100mA for KT88, B+ is 370Vdc. I also of course use a bleeder resistor of the B+
The bass was slightly sluggish regardless of the chosen mode therefore I added some Schade local feedback and now the bass is more controlled. Pink Floyd is delightful.
BR
Eric
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