Been quite busy around here, but hooked up the boards properly for a single supply.
PSU is 0-24V, gain is stock (10).
The important points to notice are -
-V is used as ground
VG (“virtual ground”) is unused
Signal ground, both input and output, must be attached to the -V ground.
-IN attached to -V ground
R10 is jumper
This works great and drives my MoFo to very loud levels, it sounds fantastic!
PSU is 0-24V, gain is stock (10).
The important points to notice are -
-V is used as ground
VG (“virtual ground”) is unused
Signal ground, both input and output, must be attached to the -V ground.
-IN attached to -V ground
R10 is jumper
This works great and drives my MoFo to very loud levels, it sounds fantastic!
Looks great!
Quick question - What type of wire are you using to connect the board output to the output jacks?
Quick question - What type of wire are you using to connect the board output to the output jacks?
What is the difference between a Frontend and a Linestage?
The preamp above could also be built using the 2018 linestage (if a -+ psu was used)?
The preamp above could also be built using the 2018 linestage (if a -+ psu was used)?
A frontend can be a linestage.
Typically a frontend is the voltage gain stage in front of the output stage of a power amplifier. In many cases the output stage is a follower with no voltage gain. So a frontend then has high gain and high maximum voltage output.
A typical linestage that is a preamp to a power amplifier usually has less gain and lower maximum power output as most power amplifiers have voltage gain also.
But for power amplifiers that have no voltage gain, a preamp needs to provide the extra voltage amplification.
Another example of a preamp that is also a frontend is the BA-3.
Typically a frontend is the voltage gain stage in front of the output stage of a power amplifier. In many cases the output stage is a follower with no voltage gain. So a frontend then has high gain and high maximum voltage output.
A typical linestage that is a preamp to a power amplifier usually has less gain and lower maximum power output as most power amplifiers have voltage gain also.
But for power amplifiers that have no voltage gain, a preamp needs to provide the extra voltage amplification.
Another example of a preamp that is also a frontend is the BA-3.
Very beautiful, congratulations! I'm just now noticing the LED floating above your SMPS filter PCB, which illuminates the chassis interior and makes the ventilation slots emit a diffused and sexy glow. Fantastic idea.
Would be interesting to hear some voltage output specs from the completed project. We can speculate on how close the output is to the Rails, but it would be nice to hear.
Not that it applies to 6L6's example, but, I'm eagerly watching for some brave soul to put 50-60volts to this gem and share the details.
Not that it applies to 6L6's example, but, I'm eagerly watching for some brave soul to put 50-60volts to this gem and share the details.
A bipolar (+/-) 24v supply would be 48V. That’s my next build. 50-60V is totally doable according to Nelson.
Regarding “front end” vs. “linestage”, it mainly comes down to how much gain you want/need. This circuit can be used as a buffer (voltage gain of 0, 0db) to having enough to drive a follower amp like MoFo, and of the recent Vfet stages, or F4 to loud levels. (Voltage gain of 10, 20db) and anywhere in between.
Regarding “front end” vs. “linestage”, it mainly comes down to how much gain you want/need. This circuit can be used as a buffer (voltage gain of 0, 0db) to having enough to drive a follower amp like MoFo, and of the recent Vfet stages, or F4 to loud levels. (Voltage gain of 10, 20db) and anywhere in between.
Well maybe… remember that the BA1 stage has the bias for the SE output boards.
So if you have complimentary (BA3 output) then yes, it would work for that.
So if you have complimentary (BA3 output) then yes, it would work for that.
Isn't the BA bias on a separate board from the gain stage for both the SE and Complimentary Output boards?
You know what, you are absolutely correct. I’ve never build the SE output stage and was thinking about the schematic without looking at it to check.
So yes, you could use this for voltage gain with either of the Burning Amp output stages.
So yes, you could use this for voltage gain with either of the Burning Amp output stages.
I think we could also 'hang' a M2X - outputsatge (or the WHAMMY -OS) with the opto-bias behind the Frontend2022...
No matching of N-ch / P-ch - MosFets strictly necessary. Many options.
Cheers
Dirk
No matching of N-ch / P-ch - MosFets strictly necessary. Many options.
Cheers
Dirk
Also check Patricks / EUVLs thoughts about the M2X-outputstage...
https://www.diyaudio.com/community/...in-class-a-b-and-maybe-a-power-whammy.390636/
Dirk 🤔
https://www.diyaudio.com/community/...in-class-a-b-and-maybe-a-power-whammy.390636/
Dirk 🤔
Thank you. I understand now the difference.
However the 2018 linestage must be a special variation as gain can be set by a feedback resistor so it can be almost at frontend?
It also has power enough to almost be able to drive headphones if the large output transistors are used which is another feature.
I can also see that I already have a frontend as I built the BA-3 pre for my MoFo. So BA-3 pre can also be called a DIY Frontend......but I guess we just needed one more DIY Frotend? 🙂 ......BA-3 is quite good.....but maybe the new one is better.......who knows 🙂 ....it is a bit simpler at least. Balanced input is mentioned also but is not used in the above preamp as far as I can see.
Are you for real? derekr, pull you ears, why don't you read carefully🙂? The answeris in #312. It's nothing personal, but.......we overreacted. It started to turn really tedious. I apologise to everyone.
Baad Papa
he didn't made it Balanced right from the box, so that one can use it with Boo
though, one can still use this with Pooh, and make nice stereo Summer amp
Greedy Boyz, if it's short of biggest Swiss Knife while being more expensive than No. 8 Opinel, it is not good enough
he didn't made it Balanced right from the box, so that one can use it with Boo
though, one can still use this with Pooh, and make nice stereo Summer amp
Greedy Boyz, if it's short of biggest Swiss Knife while being more expensive than No. 8 Opinel, it is not good enough