PASS DIY Headphone Amp - WHAMMY
Feb 5, 2019 at 3:04 PM Post #121 of 274
lol Tom that was quick.

Use my pics for the orientation, I scratched my head for a while over which way to plug it in as there are no markings on it or info in the listing. Luckily I noticed the dual version needed for the whammy is just two singles fitted to an adapter board and in the single version listing there is a helpful pin out.
 
Feb 5, 2019 at 7:54 PM Post #122 of 274
Hey guys,

Curiosity got the better of me about a month ago and I ordered one of these ebay HDAM fully discrete dual op amps from China which are based on Marantz HDAM circuit model.

It finally turned up today with delivery to the UK taking about four weeks.

Only had a brief listen so far (little one is not very happy with chicken pox) but first impressions are good which hopefully bodes well as the Burson V6 op amps took a while to burn in before they started sing so am thinking these might be similar.

https://www.ebay.co.uk/itm/Full-Discrete-DUAL-Channels-Op-Amp-Module-replace-NE5532-MUS02-OPA2604-LME49720/252473351516?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649


s-l400.jpg



Ok, this think looks like a transformer or something. Optimus prime of op amps!

Any comparisons to other op amps? All I have now is an RC4580, but I’ll be trying an Lm833 and ad823 at some point
 
Feb 6, 2019 at 3:55 AM Post #123 of 274
The first op amp I used was the LM833 which I liked and happily used it for a while before picking up a Burson V6 Classic to try. I have pretty much stuck with the Classic ever since it just seems a nice match with the hd800 headphones.

I did try a Burson V6 Vivid and I can see that being a good choice for more laid back cans but not such a good choice with the hd800.

The Chinese HDAM clone op amp has definitely improved already while listening this evening at the moment it sounds to me sort of half way between the V6 Vivid and the V6 Classic it sounds spacious and detailed like the Vivid but it is more relaxed but not so intimate and textured as the Classic. Its an enjoyable listen with the hd800.

But early days maybe if the Burson V6's are anything to go by I felt they took a good while (month or two) of use before I felt I had gotten the best out of them.
 
Feb 25, 2019 at 1:39 PM Post #124 of 274
Nice thread. Owned a few Pass amps and pre-amps, and built a large number of kits in the "old days" - Tiger, Dyna, Hafler, Heathkit... Looks like its time to build a NP design. ACA looks killer!
 
Feb 26, 2019 at 4:30 AM Post #125 of 274
The first op amp I used was the LM833 which I liked and happily used it for a while before picking up a Burson V6 Classic to try. I have pretty much stuck with the Classic ever since it just seems a nice match with the hd800 headphones.

I did try a Burson V6 Vivid and I can see that being a good choice for more laid back cans but not such a good choice with the hd800.

The Chinese HDAM clone op amp has definitely improved already while listening this evening at the moment it sounds to me sort of half way between the V6 Vivid and the V6 Classic it sounds spacious and detailed like the Vivid but it is more relaxed but not so intimate and textured as the Classic. Its an enjoyable listen with the hd800.

But early days maybe if the Burson V6's are anything to go by I felt they took a good while (month or two) of use before I felt I had gotten the best out of them.
There is this new opamp making a lot of chatter in other places

OPA2156

Also, OPA1662 has a really nice presentation of sound, very good bass and overall clean and detailed.
 
Feb 28, 2019 at 10:49 AM Post #126 of 274
I'm thinking of doing one of these amp kits, but i have absolutely no experience in soldering or putting things together.
Would it be possible for me to put this one together, or would i just mess it up and waste 200$?
 
Feb 28, 2019 at 12:46 PM Post #127 of 274
I'm thinking of doing one of these amp kits, but i have absolutely no experience in soldering or putting things together.
Would it be possible for me to put this one together, or would i just mess it up and waste 200$?

I haven't built this yet (I don't know why I keep delaying the inevitable but I keep following the WHAMMY threads), but I taught myself soldering using various amp kits in the past. The through-hole pcb design makes it very beginner friendly. The build guide and full kit available from diyaudio give you the foundation. If you watch youtube videos on proper soldering/ de-soldering through-hole components and practice on a blank through-hole board to get used to the process and temperature settings, you should be okay.

Honestly, the main determining factor of success is your attitude and persistence instead of giving up when you run into problems. When you succeed though, you will be addicted to building all sorts of things.
 
Feb 28, 2019 at 1:18 PM Post #128 of 274
looking on ebay there are loads of inexpensive practice / learn to solder projects like the ones in the link below.
There are also some clones of the Pass ACA which is a 5W Class A power amp this little amp sounds great and you would be able to use the whammy as a pre-amp driving it.

Imagine that a full Pass pre and mono block set up.

https://www.ebay.co.uk/itm/Beginner...=item59169400c6:g:4AgAAOSw29Jb7Fvv:rk:15:pf:0

https://www.ebay.co.uk/itm/NE555-CD...NdCusRdTe61fDkK66n4kBjNnjwKlYP&frcectupt=true

https://www.ebay.co.uk/itm/One-pair...6:g:viYAAOSwfrJbZtYT:rk:1:pf:1&frcectupt=true

https://www.ebay.co.uk/itm/DIY-6J5-...OqbiwHzixn0DqEQWzlNhn6HIi+Lq0R8xuENCYg3bnA7Ql
 
Feb 28, 2019 at 3:47 PM Post #129 of 274
I haven't built this yet (I don't know why I keep delaying the inevitable but I keep following the WHAMMY threads), but I taught myself soldering using various amp kits in the past. The through-hole pcb design makes it very beginner friendly. The build guide and full kit available from diyaudio give you the foundation. If you watch youtube videos on proper soldering/ de-soldering through-hole components and practice on a blank through-hole board to get used to the process and temperature settings, you should be okay.

Honestly, the main determining factor of success is your attitude and persistence instead of giving up when you run into problems. When you succeed though, you will be addicted to building all sorts of things.


looking on ebay there are loads of inexpensive practice / learn to solder projects like the ones in the link below.
There are also some clones of the Pass ACA which is a 5W Class A power amp this little amp sounds great and you would be able to use the whammy as a pre-amp driving it.

Imagine that a full Pass pre and mono block set up.

https://www.ebay.co.uk/itm/Beginner...=item59169400c6:g:4AgAAOSw29Jb7Fvv:rk:15:pf:0

https://www.ebay.co.uk/itm/NE555-CD4017-Scrolling-Flowing-Red-Light-SMD-DIY-Kit-Soldering-Practice-Kits-JT/123425111985?epid=11025738380&hash=item1cbcb5bfb1:rk:1:pf:1&checksum=123425111985d64665ceb79c462c859a6b34d166c41d&enc=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&frcectupt=true

https://www.ebay.co.uk/itm/One-pair...6:g:viYAAOSwfrJbZtYT:rk:1:pf:1&frcectupt=true

https://www.ebay.co.uk/itm/DIY-6J5-6J3-Vacuum-Tube-Class-A-Preamp-Amplifier-Board-Headphone-Amp-Kit/233086686895?hash=item36450c96af:rk:1:pf:1&checksum=23308668689507890bae403840a8ab8038aac0e0df05&enc=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

Thank you for the answers. It looks like a good idea to get some training kits first. Seems very possible though. I think I’m going to try. Maybe I’ll have some more questions in the future
 
Feb 28, 2019 at 10:07 PM Post #130 of 274
Nice thread. Owned a few Pass amps and pre-amps, and built a large number of kits in the "old days" - Tiger, Dyna, Hafler, Heathkit... Looks like its time to build a NP design. ACA looks killer!
I just completed the Nelson Pass amp camp amp kits duel mono blocks, built a linear power supplies from the PCB boards available at do it yourself audio store. Absolutely awesome little amplifier . I built BK-20 speaker cabinet design for a single full range Fostex speaker. Just crank out 1 W of power for a speaker to put out 96db,
 
Mar 1, 2019 at 7:21 AM Post #131 of 274
I just completed the Nelson Pass amp camp amp kits duel mono blocks, built a linear power supplies from the PCB boards available at do it yourself audio store. Absolutely awesome little amplifier . I built BK-20 speaker cabinet design for a single full range Fostex speaker. Just crank out 1 W of power for a speaker to put out 96db,

Very interesting. I need to make a list of Pass DIY amps that can have a 4 pin output and XLR inputs. Not that many.
 
Mar 1, 2019 at 8:12 AM Post #132 of 274
fwiw so far for driving my Hifiman HE-6 the little Pass ACA proved excellent. I have built two ACA so far on the first one I used an adapter from the ACA speaker taps. On the second I fitted a 4pin XLR out (just linked to the speaker taps internally).
 
Jun 22, 2019 at 7:10 AM Post #133 of 274
Does this (WHAMMY) 'play nice' with sensitive IEMs like Etymotics? The 'pitch' implies that it will work with 'anything' but I mean with acceptable noise levels and usable volume control range. I know it will work fine with my 250Ω Beyers but I need to use IEMs at certain times.
Looks like an easy build save for the absence of a ready-made chassis solution; any suggestions there?.
 
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Jun 22, 2019 at 11:24 AM Post #134 of 274
Does this (WHAMMY) 'play nice' with sensitive IEMs like Etymotics? The 'pitch' implies that it will work with 'anything' but I mean with acceptable noise levels and usable volume control range. I know it will work fine with my 250Ω Beyers but I need to use IEMs at certain times.
Looks like an easy build save for the absence of a ready-made chassis solution; any suggestions there?.
No, not good with sensitive stuff
 

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