Do you have a schematic? And are you happy with the sound?This my latest amp: 211 SE (20W) , all DHT tube. Input/driver tubes is 10Y/801A.
211 SE DHT AMPLIFIER
So far I am pretty happy with its sound even though it is not fully broken in. The circuit for these amps are so simple that I never bother to draw them. This full DHT is a pain because you need separate heater for each tube, and regulated heater too, for low hum.
So far I am pretty happy with its sound even though it is not fully broken in. The circuit for these amps are so simple that I never bother to draw them. This full DHT is a pain because you need separate heater for each tube, and regulated heater too, for low hum.
Do you have a schematic? And are you happy with the sound?
I understand. But am curious as to cap coupled or interstage. Am planning an all interstage GM70 with 41PL->300B->GM70 and so yes, I'll also have to build three seperate heaters for each tube. (Coleman)The circuit for these amps are so simple that I never bother to draw them.
This my latest amp: 211 SE (20W) , all DHT tube. Input/driver tubes is 10Y/801A.
I recognize your style! Your amps are fantastically beautiful!!
Are you going to bring that to Burning Amp this year?
Your build looks excellent. Great work.So far I am pretty happy with its sound even though it is not fully broken in. The circuit for these amps are so simple that I never bother to draw them. This full DHT is a pain because you need separate heater for each tube, and regulated heater too, for low hum.
211 DHT SE amplifier
This amplifier started out with capacitor coupled design, but ended up with interstage. Basically the 10Y input tube directly coupled to the second 10Y driving an interstage transformer. The output of the interstage drives the 211 in fixed bias. The interstage is hidden under the amp, it was an afterthought.
My GM70 amplifier (picture in previous page used similar circuit but with a pentode strapped triode driving a 6B4G DHT.
This amplifier started out with capacitor coupled design, but ended up with interstage. Basically the 10Y input tube directly coupled to the second 10Y driving an interstage transformer. The output of the interstage drives the 211 in fixed bias. The interstage is hidden under the amp, it was an afterthought.
My GM70 amplifier (picture in previous page used similar circuit but with a pentode strapped triode driving a 6B4G DHT.
I understand. But am curious as to cap coupled or interstage. Am planning an all interstage GM70 with 41PL->300B->GM70 and so yes, I'll also have to build three seperate heaters for each tube. (Coleman)
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Burning amp 2013.
I dont know what I am going to bring to the BA 2013, by that time, I woukl have finished more exotic amp than this 211 SE.
I dont know what I am going to bring to the BA 2013, by that time, I woukl have finished more exotic amp than this 211 SE.
I recognize your style! Your amps are fantastically beautiful!!
Are you going to bring that to Burning Amp this year?
Would you post a schematic?This amplifier started out with capacitor coupled design, but ended up with interstage. Basically the 10Y input tube directly coupled to the second 10Y driving an interstage transformer. The output of the interstage drives the 211 in fixed bias. The interstage is hidden under the amp, it was an afterthought.
My GM70 amplifier (picture in previous page used similar circuit but with a pentode strapped triode driving a 6B4G DHT.
Some nice fresh ideas are here. I like the idea of the partly hidden, angled tubes.
Me too.
Attachments
My current amplifiers have been in continuous use since October of 2011 when I completed them. They average about 30hrs a week of use, and are on their second set of tubes. Simple all transformer coupled stage design using a single GM70 and triode connected D3A per channel. The transformer coupled outputs of my line stage float and are direct coupled to the grid and bias networks for the D3As.. Fixed bias is used throughout. No coupling capacitors except in the input of the 26 dht based line stage.
Output power is a little over 20W per channel, and operate full range. The speakers are 100dB+ efficient..
Because of the high voltages involved I have not shared the design. (and won't)
I've sold all of my other amps.. These will suffice and have proven to be extremely reliable in use.
Output power is a little over 20W per channel, and operate full range. The speakers are 100dB+ efficient..
Because of the high voltages involved I have not shared the design. (and won't)
I've sold all of my other amps.. These will suffice and have proven to be extremely reliable in use.
Attachments
Ukrainian monoblocks (6B4G in PSE, no feedback, 2C51 and E288CC driver) I bought broken and had to rebuilt
what a beautiful amp !
Kevin,My current amplifiers have been in continuous use since October of 2011 when I completed them.
Because of the high voltages involved I have not shared the design. (and won't)
I've sold all of my other amps.. These will suffice and have proven to be extremely reliable in use.
What Op transformer/power Tx did you use?
(Poss PM)?
Regards
M. Gregg
All of my power and output transformers were custom built to my specifications. The power transformers for the amps were made to order by Edcor, and the output transformers by Jack Elliano at Electra-Print. The interstages were made by Lundahl.. None were terribly expensive. I use Rod Coleman CCS for heating the GM70s, and LT1084 based pre-regulators to power them. Predictable operating point in the driver stage is provided by a 20mA cascode current source that provides plate voltage to the IT. The plate supply is locally decoupled by large film caps - plate voltage is determined by the transconductance of the driver tube at approximately -2.1V of grid bias. Works quite well, and also obviates the need for a very well filtered plate supply to the driver stage. (Mine still is well filtered)
Everyday its OTL
6c33c OTL. 6np2 input and 6np6 drivers. Computer source (mpdpup on ALIX) driving TDA1541A 6np2 buffered DAC. Lightspeed attenuator. Great pairing with OTLs. Blackgates everywhere.
6c33c OTL. 6np2 input and 6np6 drivers. Computer source (mpdpup on ALIX) driving TDA1541A 6np2 buffered DAC. Lightspeed attenuator. Great pairing with OTLs. Blackgates everywhere.
Attachments
6c33c OTL. 6np2 input and 6np6 drivers. Computer source (mpdpup on ALIX) driving TDA1541A 6np2 buffered DAC. Lightspeed attenuator. Great pairing with OTLs. Blackgates everywhere.
What are the 8 Tx's for.. are they interstage or heater? Interesting heat isolation for the 6C33C's.
What kind of power out are you getting?
Regards
M. Gregg
retro-thermionic: retro-34UL power amp
This amp is my new EL34 the "retro-34UL", Signature EL34 amp. On early listening the amp sounds fast, crisp and SS like. A very natural sounding amp. Valve compliment is NOS Svetlana EL34 and Svetlana 6N1P. Edcor GXSE 6omh ultra-linear OPTs and 10H choke and power tranni are Hammond. Inter-stage caps are Jensen copper, paper and oil with pure silver leads. Biploar caps are used as bypass caps on the EL34s with ceramic sockets for the audio tubes. Rectifier valve is a Golden Dragon 5U4. OPTs are rubber mounted.
Top plate is ABS plastic and base Australian Spotted Gum (oiled). Feet are filled with lead sinkers and rubber glue, silver solder and and silver plated wire used throughout. Topology is Single-end Ultra-linear.
This amp is my new EL34 the "retro-34UL", Signature EL34 amp. On early listening the amp sounds fast, crisp and SS like. A very natural sounding amp. Valve compliment is NOS Svetlana EL34 and Svetlana 6N1P. Edcor GXSE 6omh ultra-linear OPTs and 10H choke and power tranni are Hammond. Inter-stage caps are Jensen copper, paper and oil with pure silver leads. Biploar caps are used as bypass caps on the EL34s with ceramic sockets for the audio tubes. Rectifier valve is a Golden Dragon 5U4. OPTs are rubber mounted.
Top plate is ABS plastic and base Australian Spotted Gum (oiled). Feet are filled with lead sinkers and rubber glue, silver solder and and silver plated wire used throughout. Topology is Single-end Ultra-linear.
Attachments
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