MJE 340/350 are high voltage.
Very much general purpose, slow junk.
why the datsheets have nothing to say.
Likely fine for basic regulation, when high voltage is needed.
Not good for audio signal.
Not sure why BD139/140 is not considered
Within voltage range they are ideal for audio signals.
For regulation and general purpose.
MJE243/253 are more than fine as well.
These are 15 watt packages not 7 watts like KSA1381
So also more suited for regulation and even current sources.
Since they have much higher thermal rated.
KSA1381 is basically a TO-92 type transistor put in larger TO-126 package.
So depending on application and actual thermal range needed.
Even 2n5551/5401 will work fine for small signal if high voltage is needed.
Otherwise at lower voltage there is a wide range of common transistor
for high Ft and low Noise.
Very much general purpose, slow junk.
why the datsheets have nothing to say.
Likely fine for basic regulation, when high voltage is needed.
Not good for audio signal.
Not sure why BD139/140 is not considered
Within voltage range they are ideal for audio signals.
For regulation and general purpose.
MJE243/253 are more than fine as well.
These are 15 watt packages not 7 watts like KSA1381
So also more suited for regulation and even current sources.
Since they have much higher thermal rated.
KSA1381 is basically a TO-92 type transistor put in larger TO-126 package.
So depending on application and actual thermal range needed.
Even 2n5551/5401 will work fine for small signal if high voltage is needed.
Otherwise at lower voltage there is a wide range of common transistor
for high Ft and low Noise.
BD139/140 would be fine for this amplifier, but not for the mentioned voltage regulators.
TTA/TTC are considered better and can cover wider range of projects.
Just a quick one while you're there, will you be publishing details of the TMC compensation scheme?
Best,
Cv
Best,
Cv
Nothing special there. Circle encloses TMC compensation elements. It can be even improvised on the back side of the current PCB. Not that I encourage that on already assembled builds as there is no real improvement in sound, just better distortion bragging numbers. 🙂
Thanks Tombo - it's on my to-do list to try out and as I will probably be designing my own PCB for fun might as well incorporate it, even if only for the bragging / sport 🙂
Anyone needing those for projects, should order from Mouser ASAP and wait delivery in about month.
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I recently pulled Bliss from the main system because I noticed the left channel would have lower output volume compared to the right channel. It was a random issue that I couldn't get to repeat when I tried.
Long story cut short and to the point.... The problem was the preamplifier volume pot, NOT my beloved Bliss!😀
While the amp was not in service it was a perfect time to give the 1 year check up after logging approximately 800hrs and popped the lid. There was nothing to tweak! All voltages fed from the R21 modules and bias current was exactly the same since the day the lid was last screwed down.
All the torture testing you subjected Bliss amp and R21 Modules to during verification have proven to be time well spent Tombo.
My amp is now boring, no reason to open it up anymore for tweaking (But that's a good thing)
.
Cheers!!
Long story cut short and to the point.... The problem was the preamplifier volume pot, NOT my beloved Bliss!😀
While the amp was not in service it was a perfect time to give the 1 year check up after logging approximately 800hrs and popped the lid. There was nothing to tweak! All voltages fed from the R21 modules and bias current was exactly the same since the day the lid was last screwed down.
All the torture testing you subjected Bliss amp and R21 Modules to during verification have proven to be time well spent Tombo.
My amp is now boring, no reason to open it up anymore for tweaking (But that's a good thing)
.Cheers!!
That is good to hear Vunce, did you install a better preamp volume pot by any chance?
I like it when things just keep behaving like they should.
Have a great Christmas.
Gary.
I like it when things just keep behaving like they should.
Have a great Christmas.
Gary.
That is one hell of a good preamp Vunce, don't get rid of that. I am sure you will get the pot sorted. About the only thing it has not got is gold plated RCA sockets on the rear.
Have fun with it on the bench, apparently quite easy to service due to its great layout internally.
Have fun with it on the bench, apparently quite easy to service due to its great layout internally.
I was searching for this one for quite a while, she’s not going anywhere 😉.
Yup, the pots will be easy to remove and clean.
Yup, the pots will be easy to remove and clean.
Very good Vunce, here is a link for you to look at - if you have not seen it that is.
https://liquidaudio.com.au/accuphase-c-202-service-review/
Cheers.
Gary.
https://liquidaudio.com.au/accuphase-c-202-service-review/
Cheers.
Gary.
Really glad to hear that you still enjoy this amplifier. It is in the excellent company with Accuphase C-202.
This summer I've put my Bliss on task of driving Magnepan 1.7i loudspeakers, and I'm still amazed with what I hear.
Merry Christmas to all.
So has this amplifier been on your main system since you built it? If it has, it must really be something special given the number of amplifiers we have seen you build... 😳
In marriage I'm a monogamist, but in audio I tend to be more of a polygamist with multiple amplifiers. I just can't commit to one all year round.
Bliss was my main squeeze during summertime since it has low heat dissipation for a Class A amp. During the colder months the room heater amps come out of hibernation. So far this season, USSA-5 and lhquam's HGF amps have been center stage.
But, back to your comment....Yes Bliss has "It" going on for me 🙂.
Bliss was my main squeeze during summertime since it has low heat dissipation for a Class A amp. During the colder months the room heater amps come out of hibernation. So far this season, USSA-5 and lhquam's HGF amps have been center stage.
But, back to your comment....Yes Bliss has "It" going on for me 🙂.