My first tube amp, and though it cost more than anticipated -- what diy project doesn't -- I think it's worth every $.01. Beautiful sound, makes my full range Fostex sing
Pretty standard build, Edcor XPWR035, XPSE25-8-5K, Hammond 193J, 70uF motor run cap, .22uf Auricaps, EH-EL34, JJ-GZ34, Jan-Philips 12AT7WC.
That's really a great looking project. I very much like how you did the back panel as well as the switches for what I awesome are UL/Triode and feedback.
I hope the Mrs. won't notice that the lid on one of her spice jars is missing TubelabSE for 45 and 2A3
So,
I just completed a TubelabSE to be used with 45 and 2A3.
It's more "conservative" compare to the "Cinderella Castle" for the 300B, and everything went incredibly smoothly in the construction.
Particularities are that the two 10 ohm resistor to measure the bias are mounted off board under the measuring point, and I made holes, do that the bias can be adjusted without opening the chassis.
I found the chassis in Akihabara, the Tokyo electronic district. The iron comes from Thailand, from Silk. The owner was very kind and he custom made the power transformer for me.
I am still thinking about a version of the Tubelab SE with regulated PSU, but it will take a while.
Davide
P.S.: This time pictures were taken with a Nikon
So,
I just completed a TubelabSE to be used with 45 and 2A3.
It's more "conservative" compare to the "Cinderella Castle" for the 300B, and everything went incredibly smoothly in the construction.
Particularities are that the two 10 ohm resistor to measure the bias are mounted off board under the measuring point, and I made holes, do that the bias can be adjusted without opening the chassis.
I found the chassis in Akihabara, the Tokyo electronic district. The iron comes from Thailand, from Silk. The owner was very kind and he custom made the power transformer for me.
I am still thinking about a version of the Tubelab SE with regulated PSU, but it will take a while.
Davide
P.S.: This time pictures were taken with a Nikon
Attachments
I hope that I can include these amps as a "Tubelab" amp. They are a pair of monoblocks using Tubelab's universal driver schematic. Tubelab helped with this design on the 'tubes' forum.
The amp is two DC coupled 6SN7 differential stages with constant current sinks driving a pair of MOSFET source followers driving push pull 6L6s through Tamura 6.6K output transformers. Power supply is 'Maida' style regulator 400 volts. +75 and -105 volt supplies from separate transformers with VR tubes (for fun).
Chassis were picked up in Singapore some time ago. Very thick aluminium top plate used as heat sink for MOSFETs and CCS chips.
The amp is two DC coupled 6SN7 differential stages with constant current sinks driving a pair of MOSFET source followers driving push pull 6L6s through Tamura 6.6K output transformers. Power supply is 'Maida' style regulator 400 volts. +75 and -105 volt supplies from separate transformers with VR tubes (for fun).
Chassis were picked up in Singapore some time ago. Very thick aluminium top plate used as heat sink for MOSFETs and CCS chips.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
The top plate of the chassis is about 5mm thick aluminium so is good for a heatsink. The MOSFETs are insulated with an insulator. There is a regulated power supply with a floating LM317 regulator and MOSFET pass device. Both are attached to the large heatsink at the rear of the chassis with insulators. If B+ touches the chassis it is grounded and should trip the earth leak protection breaker at the fuse box and also the fuse in the IEC connector on the chassis.
Man those are some great looking amps guys!
Can anyone tell me where to find the motor run caps that are high enough voltage to use?
I think the highest rated round one I saw was 370v.
Also, where do you get those nice transformer housings?
I love the exotic wood used on some of those enclosures.
That guy in Lebanon is only about 40 minutes south from me.
Can anyone tell me where to find the motor run caps that are high enough voltage to use?
I think the highest rated round one I saw was 370v.
Also, where do you get those nice transformer housings?
I love the exotic wood used on some of those enclosures.
That guy in Lebanon is only about 40 minutes south from me.
The secondary voltage is what I am having trouble figuring out for the SSE.
I see an Allied 6K7VG is recommended.
It has 750 VCT.
I get confused on transformer ratings because some companies show what the loaded voltage is while others show unloaded voltages.
So is this Allied PT a 375v PT?
So with a 5AR4 I get (375v * 1.31 = 491) - 17v = 474v on the output of the 5AR4.
Is that correct?
The Allied PT is only 5 amps on the 6.3vac.
I figure if I run EL34's I will need at least a 6 amp heater winding.
The Hammond 274BX has a 6 amp heater winding but it doesn't seem to get very good reviews.
The Edcor XPWR035 PT is (370-0-370) at 200mA center tapped, 6.3V (3.15-0-3.15) at 5A center tapped and 5V at 2A
So it is only 5 amps again on the 6.3 vac.
If I use 6L6GC tubes then 5 amps is enough, but I want to be able to run EL34's as well.
Funny thing is that when I look up the specs for the Allied transformer up pops a Hammond data sheet.
I see an Allied 6K7VG is recommended.
It has 750 VCT.
I get confused on transformer ratings because some companies show what the loaded voltage is while others show unloaded voltages.
So is this Allied PT a 375v PT?
So with a 5AR4 I get (375v * 1.31 = 491) - 17v = 474v on the output of the 5AR4.
Is that correct?
The Allied PT is only 5 amps on the 6.3vac.
I figure if I run EL34's I will need at least a 6 amp heater winding.
The Hammond 274BX has a 6 amp heater winding but it doesn't seem to get very good reviews.
The Edcor XPWR035 PT is (370-0-370) at 200mA center tapped, 6.3V (3.15-0-3.15) at 5A center tapped and 5V at 2A
So it is only 5 amps again on the 6.3 vac.
If I use 6L6GC tubes then 5 amps is enough, but I want to be able to run EL34's as well.
Funny thing is that when I look up the specs for the Allied transformer up pops a Hammond data sheet.
Hello all and Happy New Year, I'm ringing in the New Year listening to the Beatles my SE. Needless to say, it sounds stupendous! The build was finished late summer but I didn't have a good camera at that time so my entry was delayed. This is my humble contribution to the gallery. The case is recycled from a broken sony DVD changer. The paint is Grey Hammertone spray. Thanks to all of the generous experts on this forum who provide timely support.
