poynton said:
Cracking idea mate, il give it a go in the morning. Had too many drinks tonight as i got bored of fiddlign with electronics. lol
Loads !!!!!!!!!!! Just wait and see !!
Andy
PS. You did check that the balance control on your amp was in the centre not hard to the left ? [/QUOTE]
Haha one of my housemates actually suggested that. I never use that as my arcam is always set on 'direct' which has no control over the bass, treble and balance. it sounds far superior and eliminates the hiss.
Mayeb ADMIN needs to free up some bandwidth ready for all the posts surrounding Adfinnis amp hack in the morning to trace the cd signal 
If you want some solder let me know, i have lots, my email was a bit further back, ill post some tomorow for you m8.
Carefully check the components you removed, make sure you didnt take anything out you shouldnt. I agree with whats been suggested, first check for all the daft stuff, like lifted solder pads, scratched o/c tracks, did u remove the op amps and fit sockets (i have good ones here for u) if you did, then try swapping the opamps to see if one has failed.
best of luck
If you want some solder let me know, i have lots, my email was a bit further back, ill post some tomorow for you m8.
Carefully check the components you removed, make sure you didnt take anything out you shouldnt. I agree with whats been suggested, first check for all the daft stuff, like lifted solder pads, scratched o/c tracks, did u remove the op amps and fit sockets (i have good ones here for u) if you did, then try swapping the opamps to see if one has failed.
best of luck
sorry for the quality, its a housemates digi cam and it has contracted bad aids.
There you go. Hope that'l keep you happy for a while. Im not sure if il be able to get any fixing done this weekend as i might be heading home from uni.
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There you go. Hope that'l keep you happy for a while. Im not sure if il be able to get any fixing done this weekend as i might be heading home from uni.
ImSparticus said:Mayeb ADMIN needs to free up some bandwidth ready for all the posts surrounding Adfinnis amp hack in the morning to trace the cd signal
If you want some solder let me know, i have lots, my email was a bit further back, ill post some tomorow for you m8.
Carefully check the components you removed, make sure you didnt take anything out you shouldnt. I agree with whats been suggested, first check for all the daft stuff, like lifted solder pads, scratched o/c tracks, did u remove the op amps and fit sockets (i have good ones here for u) if you did, then try swapping the opamps to see if one has failed.
best of luck
o christ forgot to email you earlier. Argh. cheers for the advice mate. Il try to remember to email you about the samples tomorrow.
I think the admins need a new website just for my destruction derby full of cd-63's. LOL
adam
Has anyone cared to ask how the working channel sounds?
Seeing the fuse resistors R613-R616 still in place reminded me to pass along another off list change I made that violates the hazzard warnings. I replaced the two power supply fuses (and holders) with wire jumpers. I don't know if it sounds better here, but doing that usually improves other gear.
The LM4562 opamps continue to break in and sound better (go figure). The brashness has pretty much gone. If these things cost 10x what they do, they would still be a bargain! I would not have thought they could make such the difference they have.
Seeing the fuse resistors R613-R616 still in place reminded me to pass along another off list change I made that violates the hazzard warnings. I replaced the two power supply fuses (and holders) with wire jumpers. I don't know if it sounds better here, but doing that usually improves other gear.
The LM4562 opamps continue to break in and sound better (go figure). The brashness has pretty much gone. If these things cost 10x what they do, they would still be a bargain! I would not have thought they could make such the difference they have.
adfinni said:
These are DC readings? It would help to measure the AC readings, preferably when in play mode with constant signal feed. Then you should be able to see the signal input/output levels on 1,2,3,5,6,7. The power feeds on 4,8 (+11.99, - 11.73) look ok on both sides. That's how I tracked down a similar problem with mine.
Regards
Pete
Cor blimey guv'nor - is this the longest forum thread on the web yet?!
Have any of you chaps tried using the HDAMs in your 63's and 67's as an op-amp rather than a buffer?
I know there's no trace of them in your players now, but just wondered if you ever tried it in the past...
It is a discrete op-amp after all with the output tied to the inverting input. (100% NFB.)
Using the CD6000 OSE schematic it should be relatively easy to see where to cut tracks for the feedback loop.
I wondered if a single-stage, 4-pole filter based around the HDAM (with the op-amp section removed) would sound good.... or just use a good symmetric op-amp (half an LM6172 or AD826) for the differential amp and use the discrete op-amp for the second stage.
I've tried bypassing the HDAM completely, but unlike most of you I found the sound got better and worse in equal measure, and was entirely dependent on the op-amp in use. AD825 got better, AD826 got worse...as did LM6172. Apart from the AD825, the others seemed to lack bass dynamics and overall 'punchiness' without the buffer.
Another thought - a unity gain op-amp can be replaced with an open-loop buffer. I replaced the op-amp buffer in my Denon tuner with a pair of Burr-Brown BUF634 buffers and the sound improvement was absolutely immense. I wonder if anybody tried this in their Marantz.....
Just some thoughts.... first post so be gentle with me...
Have any of you chaps tried using the HDAMs in your 63's and 67's as an op-amp rather than a buffer?
I know there's no trace of them in your players now, but just wondered if you ever tried it in the past...
It is a discrete op-amp after all with the output tied to the inverting input. (100% NFB.)
Using the CD6000 OSE schematic it should be relatively easy to see where to cut tracks for the feedback loop.
I wondered if a single-stage, 4-pole filter based around the HDAM (with the op-amp section removed) would sound good.... or just use a good symmetric op-amp (half an LM6172 or AD826) for the differential amp and use the discrete op-amp for the second stage.
I've tried bypassing the HDAM completely, but unlike most of you I found the sound got better and worse in equal measure, and was entirely dependent on the op-amp in use. AD825 got better, AD826 got worse...as did LM6172. Apart from the AD825, the others seemed to lack bass dynamics and overall 'punchiness' without the buffer.
Another thought - a unity gain op-amp can be replaced with an open-loop buffer. I replaced the op-amp buffer in my Denon tuner with a pair of Burr-Brown BUF634 buffers and the sound improvement was absolutely immense. I wonder if anybody tried this in their Marantz.....
Just some thoughts.... first post so be gentle with me...
Glenn2 said:
I suspect people with passive preamps should leave the HDAM in, to retain the big bass, but people with active preamps are more likely to prefer the more detailed and natural bufferless sound.
I have read extremely positive things elsewhere on this forum re. BUF634. Something to try in the preamp at some point!!
Simon
ps Ad - please don't kill yourself mate
im off home for the weekend in a bit so no more fiddling will be possible. I have replaced some of the new parts with old resistors etc and still cant find the source of the no output from pin 7. I might have to totally start from scratch, reinstall all old parts with clean pads and leaded solder and test again after the weekend, as im pretty stumped to where to go next troubleshooting.
Probing parts with sound:
R606,C606, L602, R604, c602, r604, rd28 rd28.
parts without sound:
C608, r608, r612.
pins 1,2,3 have sound, and 7 still doesnt.
Right im off to pack. il be on later to discuss
Probing parts with sound:
R606,C606, L602, R604, c602, r604, rd28 rd28.
parts without sound:
C608, r608, r612.
pins 1,2,3 have sound, and 7 still doesnt.
Right im off to pack. il be on later to discuss
Do you have sound either side of R606?
If not then there is a short to gnd (where there is no sound).
I dont think the 10K would have gone O/C but we are talking about a serial 63 killer here LOL
If there is sound either side of R606 but none either side of R608 then you have an open circuit track between R606 and R608.
Brent
If not then there is a short to gnd (where there is no sound).
I dont think the 10K would have gone O/C but we are talking about a serial 63 killer here LOL
If there is sound either side of R606 but none either side of R608 then you have an open circuit track between R606 and R608.
Brent
Hi Glenn2,
I noticed a reduced bass aswel when i removed the HDAM but when i changed the opamp to LM4562 the bass was back again.
I use a passive preamp so maybe the LM4562 has a better cabledrive capacity then the OPA2134 i used before.
The LM4562 is getting better by the day i have to listen to my whole CD collection again.
I think its THE replacement opamp at this moment !!
Ray,
I have a 42 Ohm resistor in series with the output of the opamp is it better to remove this for a thighter bass?
I noticed a reduced bass aswel when i removed the HDAM but when i changed the opamp to LM4562 the bass was back again.
I use a passive preamp so maybe the LM4562 has a better cabledrive capacity then the OPA2134 i used before.
The LM4562 is getting better by the day i have to listen to my whole CD collection again.
I think its THE replacement opamp at this moment !!
Ray,
I have a 42 Ohm resistor in series with the output of the opamp is it better to remove this for a thighter bass?