http://www.diyparadiso.com/sedesign1.htm
I haven't heard the 300b amps but this guy knows how to design a great sounding amp. His choice of driver tubes (c3m / 2c51) should be hard to beat.
Simon
I haven't heard the 300b amps but this guy knows how to design a great sounding amp. His choice of driver tubes (c3m / 2c51) should be hard to beat.
Simon
ghpicard said:Thorsten's Legacy...
Get it before T gets it out of the air...
requires a preamp I think
ps. I already saved that one in my harddrive
JEL Deluxe
Greetings,
I'm listening to my JEL stereo version without a pre and I think it's great.
It's also pretty easy to build and parts are easy to find.
You can start cheap and upgrade as you go. I'm on version 4 having
switched all the iron from Hammond to James.
I just wish someone would give me a pair of WE 300b's .
Brian
Greetings,
I'm listening to my JEL stereo version without a pre and I think it's great.
It's also pretty easy to build and parts are easy to find.
You can start cheap and upgrade as you go. I'm on version 4 having
switched all the iron from Hammond to James.
I just wish someone would give me a pair of WE 300b's .
Brian
ps. I already saved that one in my harddrive
I built one!
Re: JEL Deluxe
I'm somewhat different that I start big (not that very big but at least quality parts). cheaper in the end.
===================
let me repeat that I require a design that doesn't require a preamp (i.e. the design has a volume control built-in)
I feel that adding a pot at the input on a design that doesn't have one is as as simple as connecting the wires.
Thank you.
Briney said:
You can start cheap and upgrade as you go. I'm on version 4 having
switched all the iron from Hammond to James.
I'm somewhat different that I start big (not that very big but at least quality parts). cheaper in the end.
===================
let me repeat that I require a design that doesn't require a preamp (i.e. the design has a volume control built-in)
I feel that adding a pot at the input on a design that doesn't have one is as as simple as connecting the wires.
Thank you.
jarthel said:
requires a preamp I think
ps. I already saved that one in my harddrive
I built one with a non-regulated but heavily filtered PS, with 45 output tubes, and custom built transformers, and it sounds fine to me. I'm using it without pre with an unmodded DVD player as a source until I can get something better, and have previously used it with several other digital sources and a tape deck (ugh) and it works fine.
You can use an EL84, an SV83 (P15P) or a C3m as a driver... I have used it with a couple of the first two and it sounds fine to me...
A pentode driver in pentode mode has its advantages.
Now, Katapum, if you could be more specific on your thumbs down, that would add to the discussion and to the OP request for help.
Gaston
ghpicard said:
I built one with a non-regulated but heavily filtered PS, with 45 output tubes, and custom built transformers, and it sounds fine to me. I'm using it without pre with an unmodded DVD player as a source until I can get something better, and have previously used it with several other digital sources and a tape deck (ugh) and it works fine.
You can use an EL84, an SV83 (P15P) or a C3m as a driver... I have used it with a couple of the first two and it sounds fine to me...
A pentode driver in pentode mode has its advantages.
Now, Katapum, if you could be more specific on your thumbs down, that would add to the discussion and to the OP request for help.
Gaston
without a pre, how do you control the volume?
put a volume pot in front.
for your requirements, i would support the JE Labs 300B DX (and use 76 in front). Not because it will be ultimate in sonics, but it will provide you a musical platform to start with and when your hand get itchy to mod, you have a good place to start.
for your requirements, i would support the JE Labs 300B DX (and use 76 in front). Not because it will be ultimate in sonics, but it will provide you a musical platform to start with and when your hand get itchy to mod, you have a good place to start.
arnoldc said:put a volume pot in front.
say thorsten's legacy has no pot in the schematic.
Is it as simple as wiring a pot to the input so I do not need to use a preamp?
If the legacy doesn't have enough gain as is, you can always increase the value of the C3M plate resistor (within reason) to increase its mu.
The downside of this mod is increasing the output impedance of the driver stage and bringing the far left of its loadline nearer the kink.
pm
The downside of this mod is increasing the output impedance of the driver stage and bringing the far left of its loadline nearer the kink.
pm
mach1 said:If the legacy doesn't have enough gain as is, you can always increase the value of the C3M plate resistor (within reason) to increase its mu.
The downside of this mod is increasing the output impedance of the driver stage and bringing the far left of its loadline nearer the kink.
pm
as it is, the legacy has no built-in volume control. Please stay away from suggestions on amps without volume control. Unless you have an idea on how to include a volume control.
I know a preamp does more than volume control but I want to limit the discussion to that for now
Just to answer your question... I added a rotary switch with selectable fixed resistors (a stagged pot). Not the ideal but it was a gift from a friend and I also cant't get make-before-break rotary switches so R-2R ladders are out of discussion.
It's the same you will get if you put a "passive preamp" between your source and your amp.
OTOH, as arnoldc told, the JE300 is a good platform to start. Not my cup of tea, I prefer the WE91A-like topologies, but it has its followers.
Gaston
It's the same you will get if you put a "passive preamp" between your source and your amp.
OTOH, as arnoldc told, the JE300 is a good platform to start. Not my cup of tea, I prefer the WE91A-like topologies, but it has its followers.
Gaston
ghpicard said:
It's the same you will get if you put a "passive preamp" between your source and your amp.
you're right. didn't thought of that.
Another vote for the JEL 300B. OK, so mine isn't exactly the same but close enough and I can't complain. Making it a stereo version makes it slightly cheaper. I did that at first but then converted to dual monoblock just to see how big the difference is. Not much sonic difference but my power tranny/trannies run cooler and B+ is slightly higher. I also tried different rectifiers, caps, resistors, grounding schemes etc.
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