A seasoned engineer with 30 years experience in building electronic circuits could have figured for himself a day ago that testing the sides of the Pumpkin for oscillation would have been easy peasy by taking either R9/R10 or R14/R15 gate resistors offline.
Part of the process is thinking for yourself.
The real engineering type would have measured each and every device himself before soldering, and tested every section of the circuit inbetween mounting on the board.
Old teach of mine said : trust is good, checking better.
Hard to communicate with someone who has total faith in the credentials, written by his own hand.
Worst case, you could have just asked someone to fix the boards for you.
Would have cost you P&P only, instead of the 10 Quid you charge for assembling DIY projects for others.
http://www.diyaudio.com/forums/swap-meet/200745-wtb-aleph-pre-amp.html#post2786620
Why are you so rude and abrasive ?
Why not just offer sound technical advice ?
Your comments about being PERFECT without any substantail evidence do you no favours.
I've admitted my failings.
I'm a systems engineer not an audio engineer.
The fault here has nothing to do with the construction, a point that you seem to miss.
Isolating either side of the amp has achieved nothing, something else that you have missed.
Caustic comments like "I am incompetent" don't bear well with your reputation.
I have repeatedly posted that Zen Mod thinks that is is a mis-match of components. Do I see any comments from you. NO.
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We all reach our limits occasionally. I have accepted that the Pumpkins were too much for me.
Why are you constantly so rude and abrasive ?
If you have technical advice to offer then offer it.
KatieandDad,
there are no words referred to you in my post. 😕
I'm here to learn not to teach.
Sorry about that. jacco vermeulen seems to have it in his head that he is brilliant, without offering any decent advice.
I picked up your post when I intended to pick up his.
Its all sorted above anyway.
I picked up your post when I intended to pick up his.
Its all sorted above anyway.
one comment on the difference of pumpkin and B1 KatieandDad, for me the B1 is a bit more on the dark side.....can be pleasant or not
one of the best sound descriptions is here
http://www.diyaudio.com/forums/pass-labs/124889-b1-buffer-preamp-49.html#post1589981
one of the best sound descriptions is here
http://www.diyaudio.com/forums/pass-labs/124889-b1-buffer-preamp-49.html#post1589981
The fault here has nothing to do with the construction
http://www.diyaudio.com/forums/pass-labs/201450-aleph-p1-7-a.html#post2799414
470nF 100V Capacitor - £0.10 : Quarndon Electronics
Your "Orange Drop" C3 carries the old Philips logo.
Buying old NOS parts for $0.15 each can be OK, provided one measures them.
You're welcome to call them the best.
Me has a very old piece of paper in the closet that reads Mil-Spec soldering certificate, could be the reason i'm rude and abrasive.
Other than that i'm a total idiot.
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one comment on the difference of pumpkin and B1 KatieandDad, for me the B1 is a bit more on the dark side.....can be pleasant or not
one of the best sound descriptions is here
http://www.diyaudio.com/forums/pass-labs/124889-b1-buffer-preamp-49.html#post1589981
Did substantially better later with its special parallel regulators. Its still not as exciting as an analogous in attention large triode tube buffer non the less (IMHO). That one would cost 10 times more to make of course, takes heaters power, ages, and its a no no to beginners due to high voltage and inexperience in building with tubes.
B1 is B1 , agree ;
making anything more complicated , especially with da toobz , isn't strictly matter of creating better , but more act of passion
making anything more complicated , especially with da toobz , isn't strictly matter of creating better , but more act of passion
Did substantially better later with its special parallel regulators. Its still not as exciting as an analogous in attention large triode tube buffer non the less (IMHO). That one would cost 10 times more to make of course, takes heaters power, ages, and its a no no to beginners due to high voltage and inexperience in building with tubes.
Is this your way of telling us less experienced members that it is not a good idea.

Hi,
finally tested my two pumpkie board one by one with music in a balanced out setting first with Up ampli ( test failed because speakers protection is always activated even if diff. offset is around 1-2-mV after caps) and after in an unbalanced output setting with my aleph 30.
In this configuration sound is present but is covered by a very loud noise like hum that seems a ground loop effect.
1)All current and voltage tests are ok.
2)Tryed to distance boards from trasfos without effect.
3) Wired all input and output as usual in my others pre hum-free.
4) Rca ground are isolated from chassis.
5)Changin' simple wire with coax wire don't produces variations on the noise level.
6)tryed boards with ugs-low voltage supply: always noise.
This pre is a very challenge for me but with your help I will win on it.😕
Ciao,
Anto
finally tested my two pumpkie board one by one with music in a balanced out setting first with Up ampli ( test failed because speakers protection is always activated even if diff. offset is around 1-2-mV after caps) and after in an unbalanced output setting with my aleph 30.
In this configuration sound is present but is covered by a very loud noise like hum that seems a ground loop effect.
1)All current and voltage tests are ok.
2)Tryed to distance boards from trasfos without effect.
3) Wired all input and output as usual in my others pre hum-free.
4) Rca ground are isolated from chassis.
5)Changin' simple wire with coax wire don't produces variations on the noise level.
6)tryed boards with ugs-low voltage supply: always noise.
This pre is a very challenge for me but with your help I will win on it.😕
Ciao,
Anto
Best idea is each one's dream and strive. Nobody should harness for anybody else.
just go for it
best way for learning something is ...... to start to learn
![]()
Well said my dear mentors. Will have to wait though, the queue is already full of other wonderful things. Perhaps next week.😀
wait 'till tomorrow , from two reasons :
- to cool your head
- to have a sun , or proper external light source for pictures
in a meantime , I'll try to find few wiring sketches I made long ago ...
- to cool your head
- to have a sun , or proper external light source for pictures
in a meantime , I'll try to find few wiring sketches I made long ago ...
Worked about six hours around it without results.You are right, I 'm so tired.
It's time to sleep.
Ciao,
Anto
It's time to sleep.
Ciao,
Anto
in a meantime , I'll try to find few wiring sketches I made long ago ...
This?

http://www.diyaudio.com/forums/pass-labs/201450-aleph-p1-7-a.html#post2799414
470nF 100V Capacitor - £0.10 : Quarndon Electronics
Your "Orange Drop" C3 carries the old Philips logo.
Buying old NOS parts for $0.15 each can be OK, provided one measures them.
You're welcome to call them the best.
Me has a very old piece of paper in the closet that reads Mil-Spec soldering certificate, could be the reason i'm rude and abrasive.
Other than that i'm a total idiot.
I've sold them now, they're off to America.
As I said, Zen Mod did state that it might be a component mis-match but no-one at the time could offer any advice.
I'm a systems engineer. To me one 0.1uF cap is the same as another until you so called "experts" tell me otherwise.
I'm now playing with my B1, which works absolutely perfectly, just trying to "Brighten" it up a bit.
We are currently at the stage of playing with the 10uF output caps. I've got all manner of caps here from Mundorfs to Chinese Audiocaps.
I'm getting a lot of suggestions which is VERY VERY useful.
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