Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

EL34 Baby Huey Amplifier
EL34 Baby Huey Amplifier
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 18th September 2019, 08:47 PM   #591
gbowling is offline gbowling  United States
diyAudio Member
 
Join Date: Jun 2008
Location: Michigan
Any opinions here on the best KT88 for the Baby Huey?

I know there are quite a few people here who are using Kt88s. I'm rounding up parts for starting my build and the only piece I have remaining are the Kt88 tubes.

Thanks, gabo
  Reply With Quote
Old 19th September 2019, 06:55 AM   #592
lordoff is offline lordoff  Bulgaria
diyAudio Member
 
Join Date: Oct 2006
Location: Sofia
Quote:
Originally Posted by gbowling View Post
Any opinions here on the best KT88 for the Baby Huey? ...
Hi gabo,
I'm in same situation like you. Just starting to collect parts and waiting for new PCBs from prasi.
But... I already have 2 matched pairs new KT88 Gold Lion :-) Will see how performs...
Opinion are welcome too...

Last edited by lordoff; 19th September 2019 at 06:59 AM.
  Reply With Quote
Old 22nd September 2019, 07:45 AM   #593
potepuh is offline potepuh  Slovenia
diyAudio Member
 
Join Date: Feb 2004
Location: Slovenia
What will be the ideal value for the external Choke instead of the R27?
  Reply With Quote
Old 22nd September 2019, 01:44 PM   #594
bandol83 is offline bandol83  France
diyAudio Member
 
Join Date: Nov 2004
Location: near Bandol, French Riviera
If you want to use a choke you can take this one : 158T Hammond Manufacturing | Mouser France

With 300 mA max, you can run the EL34 output tubes at 400 V and 50 mA safely ( https://www.jj-electronic.com/images.../el34_e34l.pdf )

I have started the BOM for the Power Supply, it is not finished yet but you can have a look at it. The high voltage capacitors are for less than 450 V version, if you want to use the 330 VAC output of the power transformer (330 x 1.4 = 462 V - 2 V = 460 V !) it is a little bit marginal and I suggest to use 500 V version even if the capacity will be lower to keep the same size, I will give suggestion later...

Rgds,
Marc
Attached Files
File Type: pdf Baby Huey MK2 Power Supply BOM.pdf (697.7 KB, 49 views)
  Reply With Quote
Old 22nd September 2019, 08:32 PM   #595
Francois G is offline Francois G  United States
diyAudio Member
 
Join Date: Jun 2004
Location: Champaign, Illinois
Marc,
Thank you for the PS and the BOM!

I checked the relay specified for the Mk 2 PS and it seems that it is specified to switch 125VDC max. I’m not sure how tightly the specs of relays are to be adhered to. Will this work in our application?

Last edited by Francois G; 22nd September 2019 at 08:34 PM. Reason: Clarification of question
  Reply With Quote
Old 23rd September 2019, 01:52 PM   #596
bandol83 is offline bandol83  France
diyAudio Member
 
Join Date: Nov 2004
Location: near Bandol, French Riviera
Hi Francois,

You are right this relay is specified at 125 VDC and 250 VAC therefor it could not be used before the rectifier either and if we use it on the primary it will be OK but we will need a separate power supply for the heaters

I am using it without problem in this power supply, may be because the two used contact are bypassed by the 10k resistor ?

If you want to be safe you have two solution :

1) replace the 10k resistor by a jumper and do not use the power on delay
2) replace the relay by a bigger one that will support the DC voltage at the power on

Here is an updated BOM with more references

Rgds
Marc
Attached Files
File Type: pdf Baby Huey MK2 Power Supply BOM.pdf (970.6 KB, 47 views)
  Reply With Quote
Old 23rd September 2019, 08:49 PM   #597
feralmeida is offline feralmeida  Spain
diyAudio Member
 
Join Date: Jan 2006
Location: vizcaya
EL34 Baby Huey Amplifier Send a message via Yahoo to feralmeida
Dear Marc

The delays use 250VAC speec relays, I don't think it's a problem possibly due to the amperage and the switched on peak includes charging the electrolytics,

if it's a bit short If this relay of the BOM is not enough, the solutions are simple (such as adapting a socket with another relay ....... small master relay with slave plus power... a small mod .... )

Thanks for all your work and patience
Regards
Fernan

P.S. revised other delays circuit, they use relays 2x10A ...1x 40A ... for a large block of capacitors PSU, I have not had problems with 2x10A

Last edited by feralmeida; 23rd September 2019 at 08:58 PM. Reason: problem pictures link
  Reply With Quote
Old 25th September 2019, 03:08 PM   #598
Francois G is offline Francois G  United States
diyAudio Member
 
Join Date: Jun 2004
Location: Champaign, Illinois
Quote:
Originally Posted by Francois G View Post
Would it make sense to take the driver supply after the regulator? Or is it better to have the driver supply sag with the B+? Would 12Vdc be enough for the driver supply?
I am still trying to understand the answer(s) to this question. As gingertube confirmed, it seems better to let the power tube negative bias float with the supply voltage. But what does that mean for the +supply to the Mosfet drivers. Sorry that I don’t have the analytical knowledge to figure this out.

Also tried to find Bas Horneman’s wiki on Baby Huey, but could not find that either. Is it still somewhere?

Last edited by Francois G; 25th September 2019 at 03:11 PM. Reason: Language correction
  Reply With Quote
Old 26th September 2019, 04:09 PM   #599
Francois G is offline Francois G  United States
diyAudio Member
 
Join Date: Jun 2004
Location: Champaign, Illinois
Default Is this thread old and tired? Over the wall?

Quote:
Originally Posted by Francois G View Post
I am still trying to understand the answer(s) to this question. As gingertube confirmed, it seems better to let the power tube negative bias float with the supply voltage. But what does that mean for the +supply to the Mosfet drivers. Sorry that I don’t have the analytical knowledge to figure this out.

Also tried to find Bas Horneman’s wiki on Baby Huey, but could not find that either. Is it still somewhere?
I have politely asked the same primary question three times and did not receive any response. Could someone reply please. To reiterate the question- does it make sense to take the +supply for the drivers AFTER the regulator? In stead of letting the regulator serve the 12v supply for the defunct relay only.

Last edited by Francois G; 26th September 2019 at 04:17 PM.
  Reply With Quote
Old 26th September 2019, 07:29 PM   #600
feralmeida is offline feralmeida  Spain
diyAudio Member
 
Join Date: Jan 2006
Location: vizcaya
EL34 Baby Huey Amplifier Send a message via Yahoo to feralmeida
That's right, the wiki seems changed
Baby Huey PP EL84 amplifier
  Reply With Quote

Reply


EL34 Baby Huey AmplifierHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Baby Huey GB PCB - EL34 Build Thread spaceistheplace Tubes / Valves 11 8th October 2018 02:04 PM
FS: partially populated Baby Huey EL34 PCBs Abszero Swap Meet 2 18th June 2018 02:40 AM
First time baby Huey amplifier build mossmamc Tubes / Valves 131 21st November 2011 07:18 PM
Building the Baby Huey EL84 pushpull amplifier Bas Horneman Tubes / Valves 0 19th October 2009 08:21 PM


New To Site? Need Help?

All times are GMT. The time now is 05:49 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki