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

Pass Labs This forum is dedicated to Pass Labs discussion.

"WHAMMY" Pass DIY headphone amp guide
"WHAMMY" Pass DIY headphone amp guide
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 10th February 2018, 01:50 PM   #21
6L6 is offline 6L6  United States
diyAudio Moderator
 
6L6's Avatar
 
Join Date: Oct 2010
Location: Denver, Colorado
"WHAMMY" Pass DIY headphone amp guide
They have nothing to do with gain and everything to do with oscillation.

Just stick one end of the resistors into the input pads and attach your signal wires to the other end, so the 2.2K are in series with the signal hots. That's what Wayne did on an earlier PCB and it worked perfectly.
  Reply With Quote
Old 10th February 2018, 02:35 PM   #22
ve6sdw is offline ve6sdw  Canada
diyAudio Member
 
Join Date: Jan 2012
Location: Olds, Alberta
"WHAMMY" Pass DIY headphone amp guide
Quote:
Originally Posted by 6L6 View Post
I think these are the right part - 531102B02500G Aavid Thermalloy | Mouser

1" pin spacing, and choose height to fit in your enclosure of choice
Thank you for your time and effort in this.
That is what I am looking for.
  Reply With Quote
Old 10th February 2018, 02:46 PM   #23
silasmellor is offline silasmellor  Denmark
diyAudio Member
 
Join Date: Nov 2016
Location: Denmark
"WHAMMY" Pass DIY headphone amp guide
Quote:
Originally Posted by 6L6 View Post
They have nothing to do with gain and everything to do with oscillation.

Just stick one end of the resistors into the input pads and attach your signal wires to the other end, so the 2.2K are in series with the signal hots. That's what Wayne did on an earlier PCB and it worked perfectly.
Thanks 6L6, i will do that!
  Reply With Quote
Old 10th February 2018, 08:19 PM   #24
silasmellor is offline silasmellor  Denmark
diyAudio Member
 
Join Date: Nov 2016
Location: Denmark
"WHAMMY" Pass DIY headphone amp guide
Ok follow up question. If i want to add a LED for power indication on frontplate, where would be a good place to tap its power? I am using LED reference for the vregs. Can i use the + lead of R10 or would that mess with the reg?
Alternatively, can i use the small unpopulated solder hole on the PSU side coming from the 7915 and reverse it with respect to gnd?
  Reply With Quote
Old 11th February 2018, 12:56 PM   #25
silasmellor is offline silasmellor  Denmark
diyAudio Member
 
Join Date: Nov 2016
Location: Denmark
"WHAMMY" Pass DIY headphone amp guide
Finished the amp and am spending time with it today. My current impression is that it just sounds natural. I am listening on AKG k712 pros and everything sounds right. I was surprised to find that it drove my DT770 600 ohms to similar levels as these (600 vs 62 ohms), anyone care to explain that? Goes without saying, they also sounded great through this amp (though i can never listen to them for very long as they feel like having my head in a vice).

A bit about the build:
Opamp is 2xOPA627. Board is an earlier rev (without the 2.2k resistors, which i added per 6L6s instructions). I got matched pairs of 2SK2013s and 2SJ313s from liubincalvin. Bias is 60 mA.

I used a chassis from audiophonics that is slightly larger than the hammond one to get some extra space. This worked nicely (though some cutting and filing was required to make connectors fit), but i had some hum problems in the beginning when touching the pot. I think this was because the anodization of the aluminium meant the backplate was not electrically connected to the rest of the case. So i put a connection between backplace and rest of chassis and filed away the anodization at both points and now the hum is gone.

I ended up running the power indicator LED from the + side of R10 and - side of R14 so that both halves share the load, and used a 3.3kohm resistor to limit the current. I realize i made a glaring mistake in not ordering any blue LEDs... woops!

The volume pot runs off a small separate board which makes it a bit easier to fit without mounting the PCB flush with the frontplate. Got a bit tight with the wiring but i think it turned out OK. All internal signal wiring is Canare L-2B2A, which is nice and thin and really easy to work with (and the only microphone wire i had lying around).

The face and backplate are my very early learning experiences from making stencils! I had some trouble getting the stencils to lie flat against the metal, which is why the outlines are bit fuzzy here and there, but hey, this is DIY (and stencils is hard!)

Thanks Wayne for a great design, and 6L6 for another well-illustrated and easy to follow guide. This was a lot of fun, and i am enjoying this amp a lot!
Attached Images
File Type: jpg IMG_5530.JPG (375.9 KB, 1535 views)
File Type: jpg IMG_5531.jpg (573.7 KB, 1528 views)
File Type: jpg IMG_5533.JPG (268.4 KB, 1494 views)
File Type: jpg IMG_5521.JPG (328.7 KB, 1445 views)
File Type: jpg IMG_5522.JPG (329.9 KB, 1439 views)

Last edited by silasmellor; 11th February 2018 at 01:00 PM.
  Reply With Quote
Old 9th March 2018, 08:16 PM   #26
osscar is offline osscar  Latvia
diyAudio Member
 
osscar's Avatar
 
Join Date: May 2009
Location: Riga, LV
Hi,
Thank you all - for nice guide and circuit .
I have now started building of "whammy" for my youngest son.
I will not use any special parts ( opa 2604 +IRF) , CRC PSU + two bridges+ regulators.
The enclosure was ordered on ebay - I changed the volume knob from black to silver and drilled holes for neutrik socket and push button switch.
tomorrow I will make pcb if everything goes well
Attached Images
File Type: jpg DSC00417.jpg (516.6 KB, 600 views)
__________________
My DIY so far: two Leach amps, Pass AB100, Pass F5, B1 buffer, Hiraga le monstre, two LM3875, LM1875, OPA549, 6C33C SE, GU32 PP, 6p3c-e PP, Marsh headphone amp.Phono - OBH-8se, Pacific RIAA, inDiscreet Phono, Whammy headphone amp.
  Reply With Quote
Old 11th March 2018, 04:29 PM   #27
osscar is offline osscar  Latvia
diyAudio Member
 
osscar's Avatar
 
Join Date: May 2009
Location: Riga, LV
PSU is working ... just missing some parts to complete PSU and amp .. (as always - it seems that everything is there - but something is not)
Attached Images
File Type: jpg IMG_20180310_1721532.jpg (400.6 KB, 507 views)
File Type: jpg DSC00418.jpg (394.2 KB, 467 views)
File Type: jpg DSC00423.jpg (425.7 KB, 414 views)
__________________
My DIY so far: two Leach amps, Pass AB100, Pass F5, B1 buffer, Hiraga le monstre, two LM3875, LM1875, OPA549, 6C33C SE, GU32 PP, 6p3c-e PP, Marsh headphone amp.Phono - OBH-8se, Pacific RIAA, inDiscreet Phono, Whammy headphone amp.
  Reply With Quote
Old 11th March 2018, 10:25 PM   #28
Frogeye is offline Frogeye  United States
diyAudio Member
 
Join Date: Sep 2012
Location: Fair Oaks, CA
Default Using Fairchild MOSFETs in WHAMMY

First, a big "thank you" to Jim and Wayne for a great project and clear build guide.
I am nearing the end on my (first) WHAMMY and am using the Fairchild FQP3N30 and FQP3P20 devices. I have checked that the pinout is the same as on the Toshiba devices in the schematic, but being a relative Noob I would like to make certain that there are no component values that I need to change before I solder in and power up the outputs. Any comments will be greatly appreciated.
OnceI'm comfortable that it is working I will start the process of fitting it in my Modushop case from the DIYA store.
Attached Images
File Type: jpg DSCN0586[1].jpg (962.0 KB, 586 views)
  Reply With Quote
Old 12th March 2018, 12:07 PM   #29
Gregje is offline Gregje  United Kingdom
diyAudio Member
 
Join Date: Oct 2009
Location: London
My Whammy runs with these FQP devices. You can just stick them in. Works great.
In my case I decreased the source resistors (to let more juice through the output stage)
and lowered the gain of the whole amp.
Also ended up with AD823 as the gain device. It gives me fantastically low 0.5mV and 1.5mV offsets.
  Reply With Quote
Old 12th March 2018, 09:22 PM   #30
wayne is offline wayne  United States
Auburn
diyAudio Member
 
wayne's Avatar
 
Join Date: Jan 2002
Location: Northern California
"WHAMMY" Pass DIY headphone amp guide
Quote:
Originally Posted by Frogeye View Post
First, a big "thank you" to Jim and Wayne for a great project and clear build guide.
I am nearing the end on my (first) WHAMMY and am using the Fairchild FQP3N30 and FQP3P20 devices. I have checked that the pinout is the same as on the Toshiba devices in the schematic, but being a relative Noob I would like to make certain that there are no component values that I need to change before I solder in and power up the outputs. Any comments will be greatly appreciated.
OnceI'm comfortable that it is working I will start the process of fitting it in my Modushop case from the DIYA store.
Yes the pinout is the same. It looks like you did a very nice job.
__________________
wizards assistant
  Reply With Quote

Reply


"WHAMMY" Pass DIY headphone amp guideHide 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
FS: Nelson Pass "CSX1/2" "Buffered F6" Front End PCBs luvdunhill Swap Meet 7 10th December 2016 03:03 PM
Small midrange boost with conical "guide" suggestions? Phenoholic Anonymus Multi-Way 11 1st December 2014 01:00 PM
Which Pass Aleph diy board for "no-cost-object" headphone amplifier? Hammerklavier Headphone Systems 43 7th August 2010 04:35 PM
The "Dummies' Guide to getting parts/assembling CarlosFM's chipamp" Spasticteapot Chip Amps 19 18th March 2006 06:17 AM


New To Site? Need Help?

All times are GMT. The time now is 07:33 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki