Topic: practicality/morality DIY UA-5 p-mod, w-mod, and t mods ??

[spcyrfc]

i have a basic understanding of soldering.  i confident in my ability to perform the digimod on a ua-5,

has anyone performed the other mods?  are they difficult and are the specs available?

thanks,
luke

edit:  changed the title due to the responses.  also checking out the Oade site and the W,P,T mod are all copywrited so i guess the DIY w-mod could not be called that, maybe something like DIY 76degrees mod or somesuch nonsense.

[keepongoin]

i think that the unknown part #s make it extremely difficult in knowing what to buy to replace the gain stages.

[Brian Skalinder]

Doug has openly posted on the Oade board the op amps he likes to use for different sonic characteristics - warm, presence, etc.  Search around, you'll find it eventually.  I think I've only seen it mentioned once or twice.  Sorry, don't recall if it was on the new or old board.  Check the new first, though, obviously.  No real specs I know of, but there's a link somewhere around here to a site with detailed, super-up-close pics of the UA-5's innards.  That might be enough.

[keepongoin]

I have cruised around looking for almost an hour, and have looked before, with no success. 

Last time I looked in a w/ mod UA5, teh specific part numbers were scratched off.

[Chuck]

I know he likes the AD712 alot.
He recommended it as a replacement for the NE5532's in a pre-amp I made.

[keepongoin]

I know he likes the AD712 alot.
He recommended it as a replacement for the NE5532's in a pre-amp I made.

is that for the warm sound, the presence sound, or the transparent sound?


I have just started checking out this site... a good read and very informative...

http://www.dself.dsl.pipex.com/ampins/webbop/opamp.htm

[dklein]

also replacing all electrolytic caps in the signal path with film caps

[Brian Skalinder]

Here you go.  (Edit: this may be back, gonna go ask the man himself.  Stand by.)  I think you gotta be logged in to view it.  Only covers warm / presence, not transparent, but there you go.

FWIW, I'm a little torn about posting it here as Doug's apparently spent plenty of time trying out different op amps by ear.  Part of me feels it's okay to post b/c there are so few people willing / able to do it themselves and it's still "within the community".  But I get paranoid about people offering the mods to others to make some cash and take business away from the Oade Bros.  At any rate, if anyone knows that I shouldn't be posting this, please let me know and I'll remove it pronto.  Thanks.

FYI, Doug simply requested I post the link to the board, not copy the text.  Good Man, Doug Oade.  :thumbsup:

[Chuck]

I know he likes the AD712 alot.
He recommended it as a replacement for the NE5532's in a pre-amp I made.

is that for the warm sound, the presence sound, or the transparent sound?


I have just started checking out this site... a good read and very informative...

http://www.dself.dsl.pipex.com/ampins/webbop/opamp.htm

He described the AD712 as being warmer. But that doesn't mean he uses it in the W-Mod UA-5 neccesarily.

[Brian Skalinder]

He described the AD712 as being warmer. But that doesn't mean he uses it in the W-Mod UA-5 neccesarily.

True.  Same comment applies to my post.  But seems like Doug enjoys providing quality information to the community, so either way...it's probably a good suggestion.

[Daryan]

He asked asked the people that know specifically what chips are used to not tell, nor would I dream of doing so.  Pay the man the money he deserves for making a box that sounds well, less than disirable in it's stock form the best value in taping!

D

[johnw]

Doug was pretty open to people doing their own experimentation on their own UA5s. He won't mod any UA5 that wasn't purchased from him and his mods are more involved than changing the op amps. If someone were to offer to switch out op amps for people with DIY UA5s, I don't see how this would compete with Doug's business, but it would sure make the sources hard to figure out (ex. AGK 481>DIY UA5 with AD712s>JB3) 

Here you go.  (Edit: this may be back, gonna go ask the man himself.  Stand by.)  I think you gotta be logged in to view it.  Only covers warm / presence, not transparent, but there you go.

FWIW, I'm a little torn about posting it here as Doug's apparently spent plenty of time trying out different op amps by ear.  Part of me feels it's okay to post b/c there are so few people willing / able to do it themselves and it's still "within the community".  But I get paranoid about people offering the mods to others to make some cash and take business away from the Oade Bros.  At any rate, if anyone knows that I shouldn't be posting this, please let me know and I'll remove it pronto.  Thanks.

FYI, Doug simply requested I post the link to the board, not copy the text.  Good Man, Doug Oade.  :thumbsup:

[jk labs]

Just a general comment on the issue of opamps.

There is a wee bit more to this issue than just having access to a part number or two. 

The voltage rails in particular will limit the number of possible opamps that will work in a given circuit.  Most anything will work with +-12 Volts and up but when the rails are at 0 Volts and +5 Volts the field narrows drastically. Several of the "hotter" opamps simply will not work with 0 and 5 Volts for lower and upper rail. These voltages are pretty common in electronics of today. The sbm-1 for example has +-7 Volts on the rails. What is possible in this unit just isn't an option in newer Sony units.

The rails also, to some extent, limit the number and effect of known tricks for getting the most from op-amps (Ref Walt Jung's work, POGEE etc).

Then there are issues like source impedance, tweaking the feedback loop, supply rail bypass, shielding,  stability problems. Susceptibility to rectify RF energy that WILL leak in.

People talk of picking "fast" op-amps but what use is that if the implementation suffers from huge overshoots and/or inaudible hf oscillations from faulty feedback caps, use of sockets, poor supply bypass and lack of groundplane? Grainyness and hard sounding opamps aren't always because the op-amp itself is inferior in any way...

Ohhh, and current feedback opamps ... :-) Elantec revolutionized the opamp long long ago but it's still not often considered as a general purpose amplifier...  The whitepapers (at intersil) are interesting for the technically inclined.

The upshot?
A) There is much more to this than just substituting parts.
B)  _Much_ can be done just by picking a reasonable opamp and optimizing around it.

Jon

[spreadheadtom]

Just a general comment on the issue of opamps.

There is a wee bit more to this issue than just having access to a part number or two. 

The voltage rails in particular will limit the number of possible opamps that will work in a given circuit.  Most anything will work with +-12 Volts and up but when the rails are at 0 Volts and +5 Volts the field narrows drastically. Several of the "hotter" opamps simply will not work with 0 and 5 Volts for lower and upper rail. These voltages are pretty common in electronics of today. The sbm-1 for example has +-7 Volts on the rails. What is possible in this unit just isn't an option in newer Sony units.

The rails also, to some extent, limit the number and effect of known tricks for getting the most from op-amps (Ref Walt Jung's work, POGEE etc).

Then there are issues like source impedance, tweaking the feedback loop, supply rail bypass, shielding,  stability problems. Susceptibility to rectify RF energy that WILL leak in.

People talk of picking "fast" op-amps but what use is that if the implementation suffers from huge overshoots and/or inaudible hf oscillations from faulty feedback caps, use of sockets, poor supply bypass and lack of groundplane? Grainyness and hard sounding opamps aren't always because the op-amp itself is inferior in any way...

Ohhh, and current feedback opamps ... :-) Elantec revolutionized the opamp long long ago but it's still not often considered as a general purpose amplifier...  The whitepapers (at intersil) are interesting for the technically inclined.

The upshot?
A) There is much more to this than just substituting parts.
B)  _Much_ can be done just by picking a reasonable opamp and optimizing around it.

Jon

huh?




+T 

[Brian Skalinder]

Link to the Oade board re-posted.  Thanks, Doug!