Ray's wisdom on Flea PSU here:
http://www.diyaudio.com/forums/digital-source/54009-marantz-cd63-cd67-mods-list-1770.html
http://www.diyaudio.com/forums/digital-source/54009-marantz-cd63-cd67-mods-list-1770.html
brilliant - thanks!
I was in the process of pricing up some bits to make one - when the very kind Ray responded about the Flea kit and offered me one of his ready modified Power supply units - at least I know i won't be blowing up my cd player now... 🙂
I was in the process of pricing up some bits to make one - when the very kind Ray responded about the Flea kit and offered me one of his ready modified Power supply units - at least I know i won't be blowing up my cd player now... 🙂
OK so my first wave of mods has been done - LM6172 op amps fitted with gold plated sockets, PSU caps upgraded, and one of Ray's excellent DIY fleas with a separate PSU fitted in place of the standard clock.....results are impressive! so now i've decided to get my hands a bit dirtier...
From reading through Ray's mod lists, there are mentions on the decoder sections about a CRIN/CROUT mod applicable to the CD67 - from what i understand so far Marantz basically wired the clock signal from the DAC to CROUT instead of CRIN directly - and by lifting a resistor/capacitor i can correct the wiring of the clock. Now I am thinking of wiring the second feed from the flea (using coax) to it instead and just bypassing the feed from the DAC (obviously I guess that will mean cutting the track near the DAC to prevent aerial effects)....is this all there is to it - i take it the CROUT doesn't need a feed at all, or does that feed anything else? Also, do I need to fit a cap between the flea and the CRIN on the decoder and finally if i connect mini coax from the flea to the decoder, should i just connect the earth at the flea end (it is using an independent power supply, but the ground is already connected to the ground plane at the DAC)?
My other query is in regard to the mod lists - i've been consulting the three x7 related mod lists - the CD67OSE, CD57 and CD67MKii OSE and noticed that there are differences in the components - in particular electrolytics replacing standard non polar ceramics and dramatically different values for some other components. Whilst some can be discounted due to the differences between standard CD57 and CD67 models, some leave me a little confused which options i should plump for - the latest one (the CD57 in that case), or the one nearest my model (a CD67mkI SE), which also happens to be the earliest option?
Thanks in advance 🙂
From reading through Ray's mod lists, there are mentions on the decoder sections about a CRIN/CROUT mod applicable to the CD67 - from what i understand so far Marantz basically wired the clock signal from the DAC to CROUT instead of CRIN directly - and by lifting a resistor/capacitor i can correct the wiring of the clock. Now I am thinking of wiring the second feed from the flea (using coax) to it instead and just bypassing the feed from the DAC (obviously I guess that will mean cutting the track near the DAC to prevent aerial effects)....is this all there is to it - i take it the CROUT doesn't need a feed at all, or does that feed anything else? Also, do I need to fit a cap between the flea and the CRIN on the decoder and finally if i connect mini coax from the flea to the decoder, should i just connect the earth at the flea end (it is using an independent power supply, but the ground is already connected to the ground plane at the DAC)?
My other query is in regard to the mod lists - i've been consulting the three x7 related mod lists - the CD67OSE, CD57 and CD67MKii OSE and noticed that there are differences in the components - in particular electrolytics replacing standard non polar ceramics and dramatically different values for some other components. Whilst some can be discounted due to the differences between standard CD57 and CD67 models, some leave me a little confused which options i should plump for - the latest one (the CD57 in that case), or the one nearest my model (a CD67mkI SE), which also happens to be the earliest option?
Thanks in advance 🙂
Hi, I am just trying to mount the three toroidals for Higlanders mod and was wondering whether I can just mount them on the outside of the back of the chassis. They are not in plastic cases so would this be safe? It would certainly be a lot easier than building a little platform and squeezing them behind the transport. Thanks! Henry
They should really be inside the case for safety reasons. The plastic film on the outside is so easy to scratch off exposing the windings.
Agree 😛. It is dangerous to expose live components outside the case apart from appearance.
The LM6171/6172 family are very dangerous things, they easily want to oscillate.
http://www.ti.com/lit/ds/symlink/lm6171.pdf
http://www.ti.com/lit/ds/symlink/lm6172.pdf
They need power supply bypassing, compensation caps and a high speed optimized PCB layout. Please look for the data sheets.
http://www.ti.com/lit/ds/symlink/lm6171.pdf
http://www.ti.com/lit/ds/symlink/lm6172.pdf
They need power supply bypassing, compensation caps and a high speed optimized PCB layout. Please look for the data sheets.
But isn't the primary winding underneath the secondary? In other words, one would have to penetrate through a layer of insulation, then secondary winding, then another layer of insulation to reach the 240V winding. Am I just being naive? Henry
OK - I found a piece of aluminium that will make a decent shelf to hold the transformers. The voices of sanity have prevailed! Henry
Hi, I am just putting the flea together - are the ferrite beads soldered to a jumper or slipped over insulated wire? Thanks! Henry
Hi Henry,
You bend a piece of wire into a U-shape, about 5mm wide (doesn't have to be insulated). Slip a ferrite on each leg and solder it to the Flea board. You can look on my Flea-page for pictures to see how it's done.
Regards,
Ray
You bend a piece of wire into a U-shape, about 5mm wide (doesn't have to be insulated). Slip a ferrite on each leg and solder it to the Flea board. You can look on my Flea-page for pictures to see how it's done.
Regards,
Ray
OK well i've taken the plunge after many nights poring over circuit diagrams and interrogating people (Thanks Ray, you are a lifesaver!)...and started modding my CD67SE. Power supply components have been upgraded, all diodes replaced with schottkys and bypass caps fitted to the new electrolytics together with a couple of new regulators. Replaced the LM6172 opamps with some LME49720HA cans with heatsinks on...resulted in a much better soundstage and more musical. Tonight i replaced some of the opamp and output components - removed the muting transistors, fitted inductors and upgraded to silmic II caps round the op-amps. I've left the HDAM circuit in place at the moment as I wanted to see how it sounds stage by stage! However, after removing the dual dc blocking caps on the output, i measured the DC offset - on pause, left is at around 24mv, right at 50mv....which sounds somewhat high! I'm measuring using a DVM in DC only mode, between the rca ground and each channel and tested numerous times!
This sounds like I need some DC blocking in place, or is this ok, or is it a result of having the HDAM circuit still in place? It's going into a Yamaha RTX-V775 AMP which is quite new so i suspect it will have DC blocking...
This sounds like I need some DC blocking in place, or is this ok, or is it a result of having the HDAM circuit still in place? It's going into a Yamaha RTX-V775 AMP which is quite new so i suspect it will have DC blocking...
24mV offset is quite alright but 50mV is considered somewhat on the high side though still acceptable. For peace of mind I have fitted 4.7uF audiophile MKP DC blockers and I cannot hear any loss in SQ.
well i still have to fit the 0.01% tol resistors in the opamp filter circuit yet, so hopefully that will bring the offset down a bit....as well as possibly binning the HDAM stage! I was looking at decent blocking caps - are these ones ok (I don't want to spend £20 on caps particularly!) - Mundorf MKP Capacitors homepage
Thanks! 🙂
Thanks! 🙂
Thanks highlander - i was looking at the Mundorf Supreme ones but they run rather pricey! for my pocket at the moment! the MKp 4.7uF 400V ones are a rather reasonable £4 each so not too bad!
50mV is indeed a bit high, but don't worry about it now. Your amp will block it at the input. It will probably come down if you bypass the HDAM and insert the 0.1% resistors.
I wouldn't invest in any DC caps right now, if you're ever going to fit the DOS stage you need the best you can get! The £4 Mundorfs will do the job, but that's about it. I'm not overly impressed by their sound...
I wouldn't invest in any DC caps right now, if you're ever going to fit the DOS stage you need the best you can get! The £4 Mundorfs will do the job, but that's about it. I'm not overly impressed by their sound...