F5, Antek out, what transformer? - 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 20th February 2013, 03:17 AM   #1
Hikari1 is offline Hikari1  United States
diyAudio Member
 
Join Date: Jun 2012
Location: Seattle
Default F5, Antek out, what transformer?

Starting a F5 build, if built chipamps w/smps and tube guitar amps but this will be my first big boy power amp build.

A few questions:

A) Antek is out of stock for a couple of months. I've got a baby due in May so I don't have much time to get this done before all free time and personal freedom will be lost. 18+18v, 400va-ish transfomers seem hard to find. I don't have the time or money for a custom job. US voltage, what's the next option other than Antek?

Two of these Avel 18+18, 250va might work. Didn't want to go dual mono but it could work. Looks like they would just fit side by side in the Diyaudio 4U case. But they would be awfully close to the heatsinks. I would rather use a single transformer.

Avel Y236651 250VA 18V+18V Toroidal Transformer 122-620

B) Is there any recommendation against using the diyaudio power supply board with the seperate diode board instead of the bridge rectifier like Pass uses?

C) This is a simple amp with few parts. Upgrading all the resistors from dale to PRP or something would be cheap. Is this a good idea? Money better spent elsewhere? Then where?

D) Pass states that the F5 is largely immune to input impedence mismatches. Why is everyone using a passive buffered preamp with this things? Seems that a single volume pot would be better if passive is your preference. Why the buffer?

E) Lots of people want more gain. Should I build it with stock resistors/gain or immediately bump up the gain with a resistor swap? I'll be using a passive preamp, possibly with a tube buffer.

Thanks.
  Reply With Quote
Old 20th February 2013, 03:42 AM   #2
diyAudio Member
 
HIPCHECK's Avatar
 
Join Date: Jun 2004
Location: ARKANSAS
Antek Toroidal Transformer | eBay

This should do it for you!

Im not 100% up on the bias/voltage/etc of F5 but this should work even if you upgrade to a hot rod version of the amp.

Steve


BUY IT NOW $70 !!!!!!!!
__________________
If a inch of duct tape will fix it, 3 feet should fix it for life!!!!

Last edited by HIPCHECK; 20th February 2013 at 03:56 AM.
  Reply With Quote
Old 20th February 2013, 03:53 AM   #3
diyAudio Member
 
Join Date: Oct 2009
Location: MD, USA
You may want to check the Primrose group-buy going on right now (check the group buy section). People are buying the transformers from Primrose which would ordinarily be a bit more pricier than Antek, but will be cheaper due to the group buy.

Primrose(SumR Audio) Toroid GB

Hope that helps.
  Reply With Quote
Old 20th February 2013, 03:54 AM   #4
diyAudio Member
 
Join Date: Feb 2009
Quote:
Originally Posted by Hikari1 View Post
Starting a F5 build, if built chipamps w/smps and tube guitar amps but this will be my first big boy power amp build.

A few questions:

A) Antek is out of stock for a couple of months. I've got a baby due in May so I don't have much time to get this done before all free time and personal freedom will be lost. 18+18v, 400va-ish transfomers seem hard to find. I don't have the time or money for a custom job. US voltage, what's the next option other than Antek?

Two of these Avel 18+18, 250va might work. Didn't want to go dual mono but it could work. Looks like they would just fit side by side in the Diyaudio 4U case. But they would be awfully close to the heatsinks. I would rather use a single transformer.

Avel Y236651 250VA 18V+18V Toroidal Transformer 122-620

B) Is there any recommendation against using the diyaudio power supply board with the seperate diode board instead of the bridge rectifier like Pass uses?

C) This is a simple amp with few parts. Upgrading all the resistors from dale to PRP or something would be cheap. Is this a good idea? Money better spent elsewhere? Then where?

D) Pass states that the F5 is largely immune to input impedence mismatches. Why is everyone using a passive buffered preamp with this things? Seems that a single volume pot would be better if passive is your preference. Why the buffer?

E) Lots of people want more gain. Should I build it with stock resistors/gain or immediately bump up the gain with a resistor swap? I'll be using a passive preamp, possibly with a tube buffer.

Thanks.
you can almost fit 3 of those avel transformers side by side in that chassis(360mm internal with)

i would have increased the gain to 22db when used with a buffer.
  Reply With Quote
Old 20th February 2013, 05:16 AM   #5
diyAudio Member
 
HIPCHECK's Avatar
 
Join Date: Jun 2004
Location: ARKANSAS
Surplus Transformer
__________________
If a inch of duct tape will fix it, 3 feet should fix it for life!!!!
  Reply With Quote
Old 20th February 2013, 05:50 AM   #6
Hikari1 is offline Hikari1  United States
diyAudio Member
 
Join Date: Jun 2012
Location: Seattle
Hipcheck: Thanks for the info...the ebay Antek has quad secondaries and is huge. It's in Seattle, I am in Seattle. That's good. What do you do w/the unused secondaries? Just tape em off? I'll look into that Plitron too. Not sure if 300va is enough though.

Bugz: Looks like the group by is gonna take another month to sort out and who knows how long to manufacture.

Audisan: Your right. Two of those Avels would fit. My math was wrong. I am a little scared of wiring for two transformers, and really is there that much benefit to going with two transformers and a single power board? I could see the benefit with seperate trannies and seperate boards but I am trying to keep it simple as this is my first build.

Thanks for the info guys. I appreciate it.
  Reply With Quote
Old 20th February 2013, 06:04 AM   #7
diyAudio Member
 
HIPCHECK's Avatar
 
Join Date: Jun 2004
Location: ARKANSAS
the Piltron is notorious for being "more than rated"

As to the 4x20 you could parrallel the secondaries and double the value or build dual supply.

I use an Antek 4x15V in my dual mono Mini Aleph. Why not build your F5 amps with dual power supply?

my Mini Aleph w/ Antek toroid:

The Mini-A
__________________
If a inch of duct tape will fix it, 3 feet should fix it for life!!!!
  Reply With Quote
Old 20th February 2013, 10:50 AM   #8
diyAudio Member
 
buzzforb's Avatar
 
Join Date: Oct 2010
Location: Burlington, NC
Group buy will end next week some time. It's up to manufacturer then.
__________________
...Shape the sound , Man!
  Reply With Quote
Old 20th February 2013, 03:50 PM   #9
diyAudio Member
 
Join Date: Feb 2009
Quote:
Originally Posted by Hikari1 View Post
Hipcheck: Thanks for the info...the ebay Antek has quad secondaries and is huge. It's in Seattle, I am in Seattle. That's good. What do you do w/the unused secondaries? Just tape em off? I'll look into that Plitron too. Not sure if 300va is enough though.

Bugz: Looks like the group by is gonna take another month to sort out and who knows how long to manufacture.

Audisan: Your right. Two of those Avels would fit. My math was wrong. I am a little scared of wiring for two transformers, and really is there that much benefit to going with two transformers and a single power board? I could see the benefit with seperate trannies and seperate boards but I am trying to keep it simple as this is my first build.

Thanks for the info guys. I appreciate it.
i would use 2 PSU boards if your using 2 trannsformers.
  Reply With Quote
Old 20th February 2013, 04:46 PM   #10
labjr is offline labjr  United States
diyAudio Member
 
Join Date: Apr 2003
Location: MA
I didn't see the group buy. Is there a parts list of what's in the kit?
  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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Addinging windings to an Antek AS-... transformer tomchr Tubes / Valves 0 3rd July 2012 09:06 PM
Wiring an Antek Transformer CarsonPratt Power Supplies 4 14th October 2011 06:42 PM
F5 - Antek 4218 Wiring Question vdi_nenna Pass Labs 17 7th May 2011 12:05 AM
Simple SE, Antek Transformer wushuliu Tubelab 6 11th February 2011 10:12 PM
FS:Antek Toroidal Transformer XEAGLEKEEPER Swap Meet 3 25th January 2011 10:18 PM


New To Site? Need Help?

All times are GMT. The time now is 07:47 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