Hey everyone!
Looking for a little direction and I will be upfront - reading schematics are my weak point (still learning) but the wiring diagrams I have coupled with this are super helpful.
I am going to be building a set of Audio Note Kit Legend 300B PSE mono blocks, info is here: ANK Audiokits - Legend MonoBlock 300B Tube Amplifier
My one concern is it uses 6SH7 as a driver tube which I am not terribly familiar and it seems many other PSE 300B (even in the Audio Note UK lineup) use 6SL7or 6SN7. I know the 6SH7 is a pentode, where as the 6SL7/6SN7 are dual triodes. Is it possible to convert the below to utilize a 6SL7 family tube and anyone know how?
Schematic info: https://i.imgur.com/t66tTeE.png
Wiring layout: Legend Mono Blocks - Album on Imgur
6SH7 data: TDSL Tube data [6SH7]
6SL7 data: TDSL Tube data [6SL7]
6SN7 data: http://tdsl.duncanamps.com/show.php?des=6SN7
Looking for a little direction and I will be upfront - reading schematics are my weak point (still learning) but the wiring diagrams I have coupled with this are super helpful.
I am going to be building a set of Audio Note Kit Legend 300B PSE mono blocks, info is here: ANK Audiokits - Legend MonoBlock 300B Tube Amplifier
My one concern is it uses 6SH7 as a driver tube which I am not terribly familiar and it seems many other PSE 300B (even in the Audio Note UK lineup) use 6SL7or 6SN7. I know the 6SH7 is a pentode, where as the 6SL7/6SN7 are dual triodes. Is it possible to convert the below to utilize a 6SL7 family tube and anyone know how?
Schematic info: https://i.imgur.com/t66tTeE.png
Wiring layout: Legend Mono Blocks - Album on Imgur
6SH7 data: TDSL Tube data [6SH7]
6SL7 data: TDSL Tube data [6SL7]
6SN7 data: http://tdsl.duncanamps.com/show.php?des=6SN7
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just one question : if you do not master reading and therefore the understanding of a schematic, why want to question the design of an amp designed by people who know and who master?
do not see anything aggressive in my question, but being myself in learning, before modifying, I build known schematics and I try to understand how they work. it is not painless but it is very formative. assemble it as it was designed, listen to it and then judge whether to modify it or not. from my experience, the tube is the simplest way to produce a sound, but it is what is harder to develop to make music. For almost three years that I put the tubes, I depanne and interview between 1 and 3 amps per month which gives me a little experience and yet, I just finished my first clone on the basis of a whole simple diagram of the power part of a hk A300, on a frame / power / opt Ami-rowe amp amp and even that, I had to dig my head to develop it. once again, it is only my opinion and it is only my opinion. 🙂
do not see anything aggressive in my question, but being myself in learning, before modifying, I build known schematics and I try to understand how they work. it is not painless but it is very formative. assemble it as it was designed, listen to it and then judge whether to modify it or not. from my experience, the tube is the simplest way to produce a sound, but it is what is harder to develop to make music. For almost three years that I put the tubes, I depanne and interview between 1 and 3 amps per month which gives me a little experience and yet, I just finished my first clone on the basis of a whole simple diagram of the power part of a hk A300, on a frame / power / opt Ami-rowe amp amp and even that, I had to dig my head to develop it. once again, it is only my opinion and it is only my opinion. 🙂
Not answering your question, but looking at the layout picture you linked to. I don't see an AC supply to the pink PCB, I presume is the heater power supply. Got to sort that out.
I changed the URL to the wiring that has all of the different steps. I guess the last slide didn't have everything!
I appreciate your concern. I can read a schematic, it just takes me a lot of time (which is fine) as it is not my career - just a hobby. I am reaching out to this community on how to potentially modify this circuit to use a more common tube that I have access to. I plan on building the circuit as is, making sure everything functions correctly and then potentially adding a switch to allow use of either 6SH7 or 6SL7 (if possible). I've mainly build guitar amps in the past!
Any suggestions on how to do so? I will research cascodes.
Cascodes are extremely versatile device . It has low noise, high gain and easy of construction. Simple wire the 2 sections in series, apply about ½Ebb to the upper grid, bias the lower as a normal triode one, and load it with a resistance of similar value like a pentode. Decouple the upper grid to cathode or earth with a low value cap, as the electrode doesn't draw current and use two, say. 470KΩ resistors between Ebb and earth. Then after check it is properly working, then rectify it in one or other way at your own taste.
Thanks for the info. I’m not familiar with that company but I sent them an email about their 6SH7GT’s. I’ll definitely build amplifier with the 6SH7 first and go from there. Exploring my options.
Wouldn’t 12SH7 not function correctly in that circuit since the heater voltage is double?
You need 12.6V for the heaters, so yes, you would need to do something different. I missed the part about this being a kit. I thought you were going off a schematic only.
ESRC is very reputable.
ESRC is very reputable.
6SH7 is a fine (if unconventional) tube for the job; and simplifies the audio path from sequential/cascode stages to a single stage. Simplicity hath virtue.
The datasheet does say some about "high gain audio" and pentodes do have more hiss than triodes; but this is a POWER amp, not a low-level amp.
Added "advantage": ALL the 6SH7 you will ever see are "golden age", not new-made. While some new-made tubes are very good, the general standard of production was a peak in 1950-1970 period.
The datasheet does say some about "high gain audio" and pentodes do have more hiss than triodes; but this is a POWER amp, not a low-level amp.
Added "advantage": ALL the 6SH7 you will ever see are "golden age", not new-made. While some new-made tubes are very good, the general standard of production was a peak in 1950-1970 period.
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