I told you that it was your fault. I don't know nothing, but I know that. You appear out pf nowhere ans start lambasting everybody. You say the B1 performs flawlessly, but originally you said it was bland and lifeless. If I had a question about getting something to work, ZM would be one of the first I would ask, and he doesn't have the 30 years of FORMAL experience you do. If the boards are bad as you say, wait for new and try again. I would bet Nelson could make some for you and they wouldn't work. If you not willing to try new boards, be quiet, or at least admit SUSY amp os over your head as it is mine.
I have been folowing this for quite a while.
On the false hope to learn sometink for when the time came...
If I could (or better if Pay pall would olowd) I would buy pumpkin board from Zen Mod right now.
I don't know much but of one thing I am prety shure, If and when I mess things up Zen Mod will be the first of many to be there to help.
One thing I have noticed on KatienandDad pictures is the burn out flux on the pads could it be that this is part of the problem?
But as I dont have 30 years experience I was expecting same other less obvious snag.
Zen Mod could you please let me know when new boards are ready to ship.
On the false hope to learn sometink for when the time came...
If I could (or better if Pay pall would olowd) I would buy pumpkin board from Zen Mod right now.
I don't know much but of one thing I am prety shure, If and when I mess things up Zen Mod will be the first of many to be there to help.
One thing I have noticed on KatienandDad pictures is the burn out flux on the pads could it be that this is part of the problem?
But as I dont have 30 years experience I was expecting same other less obvious snag.
Zen Mod could you please let me know when new boards are ready to ship.
)
Seems that sometimes the public forum is not the place for loud, ongoing and perhaps ill considered discussion over a particular problem. Particularly when the designer/supplier has offered replacement parts.
Maybe better to use private emails until the problem is resolved then post any learnings to share with others.
That way you only have to save face with one person!
Maybe better to use private emails until the problem is resolved then post any learnings to share with others.
That way you only have to save face with one person!
I sincerely don't think Andy (KatieandDad) meant to say anything bad for ZM. We all had those bad days at some point and could be frustrated quite badly.
I don't have much equipment to diagnose the problem and probably not the deep knowledge either. However, I am also very curious to see what might be the ultimate cause. If I do get my hands on these boards, I will measure whatever you guys ask me to
I don't have much equipment to diagnose the problem and probably not the deep knowledge either. However, I am also very curious to see what might be the ultimate cause. If I do get my hands on these boards, I will measure whatever you guys ask me to
A word needs to be said that these are not for the faint hearted.
I tried my best - and I'm perfectly adept with a soldering iron and an oscilloscope.
I've been building DIY for over 30 years and have NEVER had such problems.
The faults that I had are not down to poor construction.
I've sold them now.
I'm going to concentrate on brightening up the B1, which is an easy build and can be recommended to DIYers.
ZenMod did state that the problem was probabaly down to the choice of components that I employed.
NO-ONE has even tried to offere any suggestions as to where I went wrong on that count.
The Pumkins are off to America, where, hopefully, they will be rectified and give someone some enormous ploeasure.
The Shuntkys were never any problem. They both worked first time.
Those that have had success with the Pumpkin - I HERALD YOU.
WELL DONE.
Rather than scorn - why not try to help the few that have failed.
I tried my best - and I'm perfectly adept with a soldering iron and an oscilloscope.
I've been building DIY for over 30 years and have NEVER had such problems.
The faults that I had are not down to poor construction.
I've sold them now.
I'm going to concentrate on brightening up the B1, which is an easy build and can be recommended to DIYers.
ZenMod did state that the problem was probabaly down to the choice of components that I employed.
NO-ONE has even tried to offere any suggestions as to where I went wrong on that count.
The Pumkins are off to America, where, hopefully, they will be rectified and give someone some enormous ploeasure.
The Shuntkys were never any problem. They both worked first time.
Those that have had success with the Pumpkin - I HERALD YOU.
WELL DONE.
Rather than scorn - why not try to help the few that have failed.
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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
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Hi,
returned at home after vacations and before apply resistors mods as showed on cook book tested some voltage points on the two pumpie board.
So these are the results:
1) across r7 and r8 : board sx 4.85 V- 4,82 V; board dx 4,86 V-4,83 V.
2) across r24 : board sx 1,8; board dx 1,70 V.
3) across c6 : board sx 11,85 V; board dx 11,81 V.
4) across r22 : board sx 0,70 V; board dx 0,70 V.
Value at points 1-2-3 seems Ok , with slight differences compared to voltage reference schematic.
Value at point 4 is very different compared to 2,88 V showed on the schematic.
So where could be the faults? Q9, Q10 ?
R22 value is right, 47R on the two boards.
Ciao,
Anto
returned at home after vacations and before apply resistors mods as showed on cook book tested some voltage points on the two pumpie board.
So these are the results:
1) across r7 and r8 : board sx 4.85 V- 4,82 V; board dx 4,86 V-4,83 V.
2) across r24 : board sx 1,8; board dx 1,70 V.
3) across c6 : board sx 11,85 V; board dx 11,81 V.
4) across r22 : board sx 0,70 V; board dx 0,70 V.
Value at points 1-2-3 seems Ok , with slight differences compared to voltage reference schematic.
Value at point 4 is very different compared to 2,88 V showed on the schematic.
So where could be the faults? Q9, Q10 ?
R22 value is right, 47R on the two boards.
Ciao,
Anto
Anto
there is some confusion - it seems that you are looking at schematic posted by Generg , where bias referent voltage for Q9 is taken across two LEDs ;
that schematic must be early one from thread ; final one is same as in CookBook - with just one LED voltage as referent - meaning 1V93 instead of 3V86 ....... and there is probably different value for R22 also ;
so - calculus is simple , emiter voltage is LED voltage minus Ube = 1V93-0V65 = 1V28
regarding LTP current ( direct voltage across R22 ) : in any case , 16mA through 47R will give you around 0V75 ; you are certainly in ballpark with 0V7
16mA is ballpark value ; final value will be somewhat different , after setting offsets
there is some confusion - it seems that you are looking at schematic posted by Generg , where bias referent voltage for Q9 is taken across two LEDs ;
that schematic must be early one from thread ; final one is same as in CookBook - with just one LED voltage as referent - meaning 1V93 instead of 3V86 ....... and there is probably different value for R22 also ;
so - calculus is simple , emiter voltage is LED voltage minus Ube = 1V93-0V65 = 1V28
regarding LTP current ( direct voltage across R22 ) : in any case , 16mA through 47R will give you around 0V75 ; you are certainly in ballpark with 0V7
16mA is ballpark value ; final value will be somewhat different , after setting offsets
Oh Shut Up.
I've sold them and given in.
If you had offered advice rather than caustic comments I might have accepted your offer.
My credentials are not in the audio field.
I am a systems engineer as my posts declare.
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Hi Alexandr,
yeah, a few minuts after posted noticed the different R22 value on the schematic. 180R compared to the right 47R.
So all voltages values seems Ok.
Will try your resistors mods and will post the result. Waiting for a decent double 10K pot bought on ebay some days ago and not yet consigned for a final-on hifi chain- sound.
Thank you ZM for your quick and esaustive reply, as always.
Have you fun with your WD toy ?
Ciao,
Anto.
yeah, a few minuts after posted noticed the different R22 value on the schematic. 180R compared to the right 47R.
So all voltages values seems Ok.
Will try your resistors mods and will post the result. Waiting for a decent double 10K pot bought on ebay some days ago and not yet consigned for a final-on hifi chain- sound.
Thank you ZM for your quick and esaustive reply, as always.
Have you fun with your WD toy ?
Ciao,
Anto.
