hi everyone
im trying to do afew mods to a old rotel 951 as im quite fond of this player.
ive started by replacing the clock with a audio gd clock although its being powered by the orginal 805 regulator within the cd player so im guessing im not getting the best from it yet .ive also damped down the base plate and lid,im also going to swop out the blackgate caps in favour of silmic 2 caps as i like the sound these caps produce,plus i should think the original caps are pretty tired by now.
my first question is the player has in4003 diodes,im guessing i can improve on these and maybe improve the player also...but with what? any make,model number and place to source would be helpful,along with anyother tips for extracting the max out of this player while still keeping the costs of mods at sane levels.
any help would be much appricated.
smithie
im trying to do afew mods to a old rotel 951 as im quite fond of this player.
ive started by replacing the clock with a audio gd clock although its being powered by the orginal 805 regulator within the cd player so im guessing im not getting the best from it yet .ive also damped down the base plate and lid,im also going to swop out the blackgate caps in favour of silmic 2 caps as i like the sound these caps produce,plus i should think the original caps are pretty tired by now.
my first question is the player has in4003 diodes,im guessing i can improve on these and maybe improve the player also...but with what? any make,model number and place to source would be helpful,along with anyother tips for extracting the max out of this player while still keeping the costs of mods at sane levels.
any help would be much appricated.
smithie
Did one about 4-5 years ago -
So the details not to fresh in the head and possible better bits available now.
Fitted a Net Audio clock with PSU (just fitted in this slim case).
Changed the Diodes to UF4003.
OP Amps to AD826AN or OP275 (thinking the later), as its now at my sons I cant open to be sure.
Sorry for the late reply and my first post
Tim
All bought in UK, thinking mail order?
So the details not to fresh in the head and possible better bits available now.
Fitted a Net Audio clock with PSU (just fitted in this slim case).
Changed the Diodes to UF4003.
OP Amps to AD826AN or OP275 (thinking the later), as its now at my sons I cant open to be sure.
Sorry for the late reply and my first post
Tim
All bought in UK, thinking mail order?
Last edited:
Although I feel the PCM69 dac & pmd100 DF used are too much of an ultimate limiter, at a not very high level of fidelity, I'll try to be helpful.
I think you'll find the OPA134/2134 to be much more tonally rich, without unnatural coloration, than the opamps you mention, but it's essential to give any of these much more generous & clean power supply than stock unit. The UF4003's are a bit pointless, as without being soft recovery, speed offers little sonic benefit. Better to use IRC HFA-series or IXYS dsei-series soft recovery types, which will actually make a substantial difference. As you seem to know, it's quite important to give the clock a power supply that is well isolated & as clean as possible. At the least, you should put a decent size inductor, followed by a big lytic & film, between clock & 7805, and ideally give it it's own 5v reg. On the output of the analog, you should darn well be able to simply eliminate any dc blocking caps that may or may not be in the signal path. Should be 0VDC on the opamp out lines.
I think you'll find the OPA134/2134 to be much more tonally rich, without unnatural coloration, than the opamps you mention, but it's essential to give any of these much more generous & clean power supply than stock unit. The UF4003's are a bit pointless, as without being soft recovery, speed offers little sonic benefit. Better to use IRC HFA-series or IXYS dsei-series soft recovery types, which will actually make a substantial difference. As you seem to know, it's quite important to give the clock a power supply that is well isolated & as clean as possible. At the least, you should put a decent size inductor, followed by a big lytic & film, between clock & 7805, and ideally give it it's own 5v reg. On the output of the analog, you should darn well be able to simply eliminate any dc blocking caps that may or may not be in the signal path. Should be 0VDC on the opamp out lines.
Thanks for the reply, although I stated this was with my son, he is no longer using it. Think I may have to reacquire it to play again.
From your advice above I'm thinking your comments on the DAC/OPAmp that this maybe the way to go?
http://www.diyaudio.com/forums/digital-source/186245-dac-2496-ak4393-dac-kit-cs8416-ak4393-5532-a-2.html
This may also render the cleaning up of the PS a little pointless, as the DAC has its own?
Any comment more than welcomed.
PS Just getting back into electronics (never did audio before). Looking at the affordable transport thread with great interest, DAC first; next logical step?
From your advice above I'm thinking your comments on the DAC/OPAmp that this maybe the way to go?
http://www.diyaudio.com/forums/digital-source/186245-dac-2496-ak4393-dac-kit-cs8416-ak4393-5532-a-2.html
This may also render the cleaning up of the PS a little pointless, as the DAC has its own?
Any comment more than welcomed.
PS Just getting back into electronics (never did audio before). Looking at the affordable transport thread with great interest, DAC first; next logical step?
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