Pumpkin preamp - ordered by Steen , official making thread - Page 344 - diyAudio
Go Back   Home > Forums > Amplifiers > Pass Labs

Pass Labs This forum is dedicated to Pass Labs discussion.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 7th December 2012, 05:57 AM   #3431
tonimxp is offline tonimxp  Italy
diyAudio Member
 
Join Date: Oct 2007
Location: Gallarate (VA)
Quote:
Originally Posted by Zen Mod View Post
perfect

just take care of pinout




they're good , of course

attached pic - view from top (as a bird ....... or Batman )
Good Morning Alex and...many...many thanks,also for Batman and his view on from the sky
  Reply With Quote
Old 21st December 2012, 07:36 AM   #3432
tonimxp is offline tonimxp  Italy
diyAudio Member
 
Join Date: Oct 2007
Location: Gallarate (VA)
Default Shunty little poblem/curiosity

Hi for everybody and merry chrystmas!
I need to know if this 25Mhz 7Vrms (see pictures attached) found out from my shunty is normal or not.
Have you tried to do an analysis of the output voltage of your shunty?
I believe however that should not be a problem ,but it would be interesting to ask what can be generated by this high frequency and if is possible somehow solve this little problem..
Thanks

Antonio
Attached Images
File Type: jpg IMG_20121220_172323.jpg (612.6 KB, 182 views)
File Type: jpg IMG_20121220_172343.jpg (581.4 KB, 154 views)
File Type: jpg IMG_20121220_172843.jpg (536.8 KB, 142 views)
File Type: jpg IMG_20121220_173417.jpg (448.6 KB, 168 views)

Last edited by tonimxp; 21st December 2012 at 07:42 AM.
  Reply With Quote
Old 21st December 2012, 08:42 AM   #3433
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
my specimens were dead silent , also confirmed in AR2's small DIY lab

what type of output (final) caps are you having ?

for test - try snubber RC cell across them

say 1uF and 15R in series
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa... by Mighty ZM
  Reply With Quote
Old 21st December 2012, 08:49 AM   #3434
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
put 1nF between B and C on BDX

one of "problems" is that mine (BDX-es) are genuine from yore times
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa... by Mighty ZM
  Reply With Quote
Old 21st December 2012, 10:58 AM   #3435
tonimxp is offline tonimxp  Italy
diyAudio Member
 
Join Date: Oct 2007
Location: Gallarate (VA)
I have a BC Philips brand,so... i have to put a 1uF and 15R in series between the legs of C14 and C14A?
Or a have to

put 1nF between B and C on BDX-es

Or both?

Your quote:

"one of "problems" is that mine (BDX-es) are genuine from yore times"

Sorry i didn't understand which means!

But....this spurious frequency may cause problems or not on the quality sound of the preamp?

Thanks!

Sorry my mistake the spurious is 25Mhz 7mVrms [/B]and NOT 7Vrms

Quote:
Originally Posted by Zen Mod View Post
my specimens were dead silent , also confirmed in AR2's small DIY lab

what type of output (final) caps are you having ?

for test - try snubber RC cell across them

say 1uF and 15R in series

Last edited by tonimxp; 21st December 2012 at 11:04 AM.
  Reply With Quote
Old 21st December 2012, 02:43 PM   #3436
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
Quote:
Originally Posted by tonimxp View Post
I have a BC Philips brand,so... i have to put a 1uF and 15R in series between the legs of C14 and C14A?
Or a have to

put 1nF between B and C on BDX-es

Or both?

....[/COLOR]
both

Quote:
Originally Posted by tonimxp View Post
........
Your quote:

"one of "problems" is that mine (BDX-es) are genuine from yore times"

Sorry i didn't understand which means!

.......[/COLOR]
that means - during development and in first specimens I had genuine parts from old stash ; especially BDX transistors - being darlington , their quality is crucial ; problem is "problem" , meaning that I didn't checked functionality of Shunty with less than optimal parts ; less optimal - meaning not so good BDX ( fluffy production or even fake)

Quote:
Originally Posted by tonimxp View Post
.......

But....this spurious frequency may cause problems or not on the quality sound of the preamp?

Thanks!

Sorry my mistake the spurious is 25Mhz 7mVrms [/B]and NOT 7Vrms
7mV is big difference from 7V

it will probably not change much in preamp function , but there is also possibility that oscillation is result of dirty surround (regarding RF) and suboptimal test setup

those dummy load resistors are pretty big ; try to connect satellite dish to them .....
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa... by Mighty ZM
  Reply With Quote
Old 21st December 2012, 04:04 PM   #3437
tonimxp is offline tonimxp  Italy
diyAudio Member
 
Join Date: Oct 2007
Location: Gallarate (VA)
Alex as you know i'm a policeman and i have to find the rot in everything I do but I must say that you are a great man!
I solved putting 1nF between B and C on BDX-es only!
Now the shunty is ok on all range of frequency, absolutly silent as a grave!
Alex please,have you tell me that i need to change the BDX yet or it is irrilevante now ,and have you some other advice for me?

Thanks again Alex!
Attached Images
File Type: jpg IMG_20121221_164508.jpg (123.0 KB, 131 views)
File Type: jpg IMG_20121221_171208.jpg (531.4 KB, 45 views)
File Type: jpg IMG_20121221_171217.jpg (533.2 KB, 20 views)
File Type: jpg IMG_20121221_171323.jpg (685.3 KB, 43 views)
File Type: jpg IMG_20121221_171618.jpg (685.6 KB, 78 views)
  Reply With Quote
Old 21st December 2012, 06:34 PM   #3438
tonimxp is offline tonimxp  Italy
diyAudio Member
 
Join Date: Oct 2007
Location: Gallarate (VA)
Other Mistakesorry i'm tired

Solved putting 1uF end not 1nF between B and C on BDX-es only!

Thanks!
  Reply With Quote
Old 21st December 2012, 06:49 PM   #3439
Zen Mod is offline Zen Mod  Serbia
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
Quote:
Originally Posted by tonimxp View Post
Other Mistakesorry i'm tired

Solved putting 1uF end not 1nF between B and C on BDX-es only!

Thanks!
please - try decreasing that ....... leave smallest value which is curing oscillation
1uF is way too much



Quote:
Originally Posted by tonimxp View Post
........ is irrilevante now ,and have you some other advice for me?

......

if cap cures that , of course that is irrilevante (oh , boy ,Io adoro lingua italiana ) .........

advice - turn of that soldering tool , and start with Vino ......
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa... by Mighty ZM
  Reply With Quote
Old 21st December 2012, 07:28 PM   #3440
tonimxp is offline tonimxp  Italy
diyAudio Member
 
Join Date: Oct 2007
Location: Gallarate (VA)
Alex as I said now shunty is perfect! Why to change again, in my city there is a proverb "Never change a winning team." But you are the "Boss"......so . if you want ,please tell me what value and type of capacitor i should use and I will do.

About Vino.........

Barolo..Montepulciano....Nebbiolo....or my prefered NEGRAMARO (land of Puglia where i'm born).Don't forget that if you come at Malpensa aerport ,let me know,becouse i work here and i will pleasure to meet you and give you a bottle di Negramaro.

Quote:
Originally Posted by Zen Mod View Post
please - try decreasing that ....... leave smallest value which is curing oscillation
1uF is way too much






if cap cures that , of course that is irrilevante (oh , boy ,Io adoro lingua italiana ) .........

advice - turn of that soldering tool , and start with Vino ......
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



New To Site? Need Help?

All times are GMT. The time now is 03:46 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2