The "$250" Amp? - 6LU8 Compactron SE, UL
- Thread starter Wigwam Jones
- Start date
I think I ordered a set of GXSE's
The diamond plate was laying in a pile of aluminum sheet, I bought two pieces of diamond plate and three pieces of plain sheet, larger then the diamond plate for a little over $5.
... the fold on the front of that piece was what fired up the old noodle.
Last edited:
GOYA
Super Member
rage
Well-Known Member
If I decide to go parallel output tubes after the initial build will I need different output transformers if running the XSE15-8s?
I'm leaning more toward tube rectification given that I won't save much buying expensive SS diodes.
Thanks Dave for your prompt answer on the tube socket!
edit: Speaking with Kegger I should be in good shape with the XSE15-8s... Particularly given my Forte 4 ohm woofers.
I'm leaning more toward tube rectification given that I won't save much buying expensive SS diodes.
Thanks Dave for your prompt answer on the tube socket!
edit: Speaking with Kegger I should be in good shape with the XSE15-8s... Particularly given my Forte 4 ohm woofers.
Last edited:
Layout
Here is the layout I am currently thinking about;
Edcors in back, 6LU8's up front and the rectifier tube in the middle.
Oak sides, stainless wrapped with oak for the back, with the RCA jacks, binding posts and IEC plug. stainless sheet bottom with feet.
I want to put a nice bakelite spst switch I found at a local auction, in the center of the oak front, and am still working that one out.
Here is the layout I am currently thinking about;
Edcors in back, 6LU8's up front and the rectifier tube in the middle.
Oak sides, stainless wrapped with oak for the back, with the RCA jacks, binding posts and IEC plug. stainless sheet bottom with feet.
I want to put a nice bakelite spst switch I found at a local auction, in the center of the oak front, and am still working that one out.
Attachments
I have finished designing the box to build the compactron on.
The wood is reclaimed oak, the second two pics show what the amp will probably look like.
The antek will be located underneath between the Edcors, with the radiodaze running down the center of the diamond plate.
Each channel's wiring and parts will be along the sides of the amp.
The hole in the front is to mount the power on/off switch.
No to figure the locations of each item and then drill all the holes.
The wood is reclaimed oak, the second two pics show what the amp will probably look like.
The antek will be located underneath between the Edcors, with the radiodaze running down the center of the diamond plate.
Each channel's wiring and parts will be along the sides of the amp.
The hole in the front is to mount the power on/off switch.
No to figure the locations of each item and then drill all the holes.
Attachments
rage
Well-Known Member
Anyone care to guess if I'll still need a separate transformer for the heaters for the 6LU8 if I run damper diodes? I'll be using mono-blocks and have two of the Antek power transformers, if that makes a difference.
your chassis looks great clifwst!
edit:
http://www.antekinc.com/pdf/AN-3T275.pdf
looks like 2 4 amp taps at 6.3v... I'm set! Sweet!
The slower ya'll get at replying the better I get at doing my own homework!
your chassis looks great clifwst!
edit:
http://www.antekinc.com/pdf/AN-3T275.pdf
looks like 2 4 amp taps at 6.3v... I'm set! Sweet!
The slower ya'll get at replying the better I get at doing my own homework!
Last edited:
BIGSEE's compactron build
I've currently been working on my compactron amp for about 2 months including ordering and waiting. I have about 25 hours into the build in total at the moment. In the end my plan is to have a compactron that will run 2 tubes in parallel (single ended) on the pendode section for each channel and to have a UL/Triode switch wired into the circuit. Currently my chassis is all set up for the final build but the electronics are the pure original compactron build wired for SEUL and only one tube per channel. I'm doing it in stages as a learning tool as this is my very first DIY audio build. The goal is to see what the audible difference is between each stage: Original build, add bypass caps, add second pentode section to the output, add UL/Triode mode switch. Check out the pics and let me know what you think. It will be at this months SMAC meet for those interested in seeing it/listening to it.
I've currently been working on my compactron amp for about 2 months including ordering and waiting. I have about 25 hours into the build in total at the moment. In the end my plan is to have a compactron that will run 2 tubes in parallel (single ended) on the pendode section for each channel and to have a UL/Triode switch wired into the circuit. Currently my chassis is all set up for the final build but the electronics are the pure original compactron build wired for SEUL and only one tube per channel. I'm doing it in stages as a learning tool as this is my very first DIY audio build. The goal is to see what the audible difference is between each stage: Original build, add bypass caps, add second pentode section to the output, add UL/Triode mode switch. Check out the pics and let me know what you think. It will be at this months SMAC meet for those interested in seeing it/listening to it.
Kegger
R.I.P. 1/12/1966 - 6/1/2017
Hey I recognize that.. Very nice result Chris, hope it indeed sounds great..
One thing I'd like to mention, Chris used the Edcor power tranny and it is like
a Hammond 270 series, about 320v unloaded from a 275-0-275 tranny, didn't
measure it ahead of time so his B+ is 350v, 10v loss in the outputs an 40v on
the cathodes still puts us at 300v plate to cathode along with that larger 750
ohm cathode resistor shakes out pretty good, fairly high dissipation but these
6LU8's are quite underrated for audio use compared to there TV use specs..
(a 3uf input cap on the power supply should get voltage down to around 315v)
He has 1 blastin Compactron Amp, I need to hear it an see if it sounds different.
(I think he'll be fine with the extra dissipation and we'll leave it be/check it out)
-----------
Also for those posting pictures it's really better to NOT use a hosting site, quite
often later on down the road the pic's disappear an a thread can become useless.
One thing I'd like to mention, Chris used the Edcor power tranny and it is like
a Hammond 270 series, about 320v unloaded from a 275-0-275 tranny, didn't
measure it ahead of time so his B+ is 350v, 10v loss in the outputs an 40v on
the cathodes still puts us at 300v plate to cathode along with that larger 750
ohm cathode resistor shakes out pretty good, fairly high dissipation but these
6LU8's are quite underrated for audio use compared to there TV use specs..
(a 3uf input cap on the power supply should get voltage down to around 315v)
He has 1 blastin Compactron Amp, I need to hear it an see if it sounds different.
(I think he'll be fine with the extra dissipation and we'll leave it be/check it out)
-----------
Also for those posting pictures it's really better to NOT use a hosting site, quite
often later on down the road the pic's disappear an a thread can become useless.
Well I had that conversation with douglas at the last smac meet and he seems to think the the coil orientation is turned 90 degrees on the power transformer so I believe that achieves the same goal, but I'm not totally positive. I'd have to take off the bell housings to be sure. From the shape it looks like the windings are horizontal on the outputs and verticle on the power trans. I'm a beginner and this is my first build so what do I know.
Kegger
R.I.P. 1/12/1966 - 6/1/2017
I believe that is the way it is here, BUT if there is any hum we may want to try turning
the power tranny or both outputs, I'm leaning in the direction that Douglas is correct in
this instance and no noise issues should arise from this setup.
Yah without taking the tranny's apart I couldn't say for sure, Hopefully we have it right.
the power tranny or both outputs, I'm leaning in the direction that Douglas is correct in
this instance and no noise issues should arise from this setup.
Yah without taking the tranny's apart I couldn't say for sure, Hopefully we have it right.