Hi all,
I just opened the Rotel up and took a look inside. Very impressive, it looks like it should sound much better than it does! It's absolutely chock full of Black Gates caps (pretty much every visible cap in the picture is a BG).
The chassis is solid. I can't find any op-amps, is there a discrete buffer?? The xtal is 11.2mhz, which is slightly annoying. The transport mechanism is large and fairly impressive.
I wonder why it only sounds "nice" and not "lifelike"
Simon
I just opened the Rotel up and took a look inside. Very impressive, it looks like it should sound much better than it does! It's absolutely chock full of Black Gates caps (pretty much every visible cap in the picture is a BG).
The chassis is solid. I can't find any op-amps, is there a discrete buffer?? The xtal is 11.2mhz, which is slightly annoying. The transport mechanism is large and fairly impressive.
I wonder why it only sounds "nice" and not "lifelike"
Simon
Attachments
Hi Simon,
This unit is actually a nice sounding CD Player. I am not sure why you describe the sound the way you do but it is either you are really spoiled with the Marantz or something isn't quite right. Do you need a Technical Manual with the schematic? I can email it to you. Send me your email address.
Do you have a scope? Maybe before you Mod it, you can check to see if everything is operating properly! It sounds like something is wrong because most people are quite surprised on how well it sounds stock.
There units are built like Tanks and are also laid out very nicely on a high quality PCB.
The op amps are 5534s (I don't know what manufacterer Rotel uses the prefix XR5534) and are not far from the output wires. The OPA627AP would be a nice choice for this unit and we can talk more about that later. The rail voltages are +/- 15 volts.
The Transport is a Philips CD4/19 and is pretty good and parts are available so that makes it even better.
After you determine this is running properly there is a list of mods that would be what I am either already doing or will do! Most are from what i learned from a lot of top guys in the forum.
But first check it out and fix it if necessary. Then listen for a while. Then clip out the Muting transistors (2 for each channel) one channel at a time and listen to the difference in between doing the second channel. The four muting transistors are by the output wire and look like four black half moons. T109 to T112. See the attachment of the output stage.
Let me know what you find!
Regards//Keith
This unit is actually a nice sounding CD Player. I am not sure why you describe the sound the way you do but it is either you are really spoiled with the Marantz or something isn't quite right. Do you need a Technical Manual with the schematic? I can email it to you. Send me your email address.
Do you have a scope? Maybe before you Mod it, you can check to see if everything is operating properly! It sounds like something is wrong because most people are quite surprised on how well it sounds stock.
There units are built like Tanks and are also laid out very nicely on a high quality PCB.
The op amps are 5534s (I don't know what manufacterer Rotel uses the prefix XR5534) and are not far from the output wires. The OPA627AP would be a nice choice for this unit and we can talk more about that later. The rail voltages are +/- 15 volts.
The Transport is a Philips CD4/19 and is pretty good and parts are available so that makes it even better.
After you determine this is running properly there is a list of mods that would be what I am either already doing or will do! Most are from what i learned from a lot of top guys in the forum.
But first check it out and fix it if necessary. Then listen for a while. Then clip out the Muting transistors (2 for each channel) one channel at a time and listen to the difference in between doing the second channel. The four muting transistors are by the output wire and look like four black half moons. T109 to T112. See the attachment of the output stage.
Let me know what you find!
Regards//Keith
Keith,
I'm so glad you replied, and thanks a million for sending the files, it's much appreciated.
I'm actually giving this thing more of a serious listen now and I would like to put my comments into perspective. Firstly, the player is working flawlessly, there's clearly nothing wrong with it.
I am rather spoilt by my Marantz, which has Black Gates all around, external power supplies, reclocked DAC & separately reclocked servo, plus a nice discrete class A output stage. So my reference is good, about on a par with a moderately modified Naim CD5 overall.
I would now like to say that I enjoy the music coming out of my speakers right now a lot! It's really not bad at all: extremely smooth and sweet. But it does appear to be quite coloured - not entirely neutral. Perhaps this is the Black Gate sound to some extent... The bass is big and bold but not very extended and lacking some texture. It's a chesty mid-bass sound.
The treble, whilst inoffensive, is indistinctive (jittery perhaps?) and does not vary in colour massively from track to track as with the CD63. The instruments can get a little confused when played together (on Diana Krall, for example). The timing here is also a bit lazy and sloppy. Things don't accelerate and slow down as I'm used to on, for example, Black Crow (The Girl in the Other Room). The piano is a bit plinky-plonky too, in absolute terms.
I absolutely understand why any sane person would like this sound and it's surprisingly good for the age and what I paid for it (next to nothing). This is, for my cash, a better player to buy second hand than a Marantz CD63KI.
I'm excited to hear what it can do with a few modifications. The first of which will be to put a new plug on (or replace) the mains lead. The pins are filthy.
I'm so glad you replied, and thanks a million for sending the files, it's much appreciated.
I'm actually giving this thing more of a serious listen now and I would like to put my comments into perspective. Firstly, the player is working flawlessly, there's clearly nothing wrong with it.
I am rather spoilt by my Marantz, which has Black Gates all around, external power supplies, reclocked DAC & separately reclocked servo, plus a nice discrete class A output stage. So my reference is good, about on a par with a moderately modified Naim CD5 overall.
I would now like to say that I enjoy the music coming out of my speakers right now a lot! It's really not bad at all: extremely smooth and sweet. But it does appear to be quite coloured - not entirely neutral. Perhaps this is the Black Gate sound to some extent... The bass is big and bold but not very extended and lacking some texture. It's a chesty mid-bass sound.
The treble, whilst inoffensive, is indistinctive (jittery perhaps?) and does not vary in colour massively from track to track as with the CD63. The instruments can get a little confused when played together (on Diana Krall, for example). The timing here is also a bit lazy and sloppy. Things don't accelerate and slow down as I'm used to on, for example, Black Crow (The Girl in the Other Room). The piano is a bit plinky-plonky too, in absolute terms.
I absolutely understand why any sane person would like this sound and it's surprisingly good for the age and what I paid for it (next to nothing). This is, for my cash, a better player to buy second hand than a Marantz CD63KI.
I'm excited to hear what it can do with a few modifications. The first of which will be to put a new plug on (or replace) the mains lead. The pins are filthy.
I will take the Rotel up to see my friend Brent tomorrow (Rowemeister) as he has been fixing my CD63 (don't ask), and we'll discuss where it should perhaps go in terms of upgrades.
I didn't take the pcbs out earlier but I couldn't see any op-amps, only markings for two DIP-size chips. I can't see where they're hidden but I assume it must be under that big piggy-backed board, as that's the best place to hide.
Simon
I didn't take the pcbs out earlier but I couldn't see any op-amps, only markings for two DIP-size chips. I can't see where they're hidden but I assume it must be under that big piggy-backed board, as that's the best place to hide.
Simon
SimontY said:
Simon,
The schematics for the 865 and 965 analogue opamps and PSU look very similar. I've got the 965, which were fitted with 220uF panny HFS caps after the 7xx15 regs, instead of 47Uf as specified in the technical manual. Modded it in several places, but my first mod was changing the caps to 47uf, and this changed the character of the bass dramatically from dull, warm, thick to tight lean bass, which I like.
Hi Simon,
I am glad you got a chance to define what you were listeninng to. Now you know what it does well and what it does average. Although it is loaded with Blackgates, they aren't the end all. A lot has changed since the late 80s.
So what to do:
First cut out the Muting transistors. Noise and pops are next to nothing (I listen loud and it is no problem).
If you want to start with a decent Power cord and IEC Inlet with better wiring to the mains, I highly recommend it (although the hot passes through the switch and then a fuse). Places of degradation in my opinion.
These really benefit from Clean power so figure where you will get the best bang for the buck with the right caps and diodes and rectifiers (I haven't gotten there yet).
You might also choose additional power/regulators for a new clock and for the DAC. Another significant improvement in these. (Not there yet either).
Clock is paramount!
Better caps to decouple the DAC might help, maybe the other guys can assist on this.
My choice for new op amps was OPA627APs because they will add some warmth. There are some great ADxxx op amps that apply but although they are articulate and detailed, they are a little too cold for this CDP IMO (already a little cold). If you experiment, use sockets. I almost trashed my PCB soldering too much and op amps get expensive if you have to cut all of them out.
As far as Biasing to Class A, well some of the guys I respect most suggest not to but I may experiment just to satisfy my curiosity. So many and especially Carlosfm rave about this mod. Although I don't think it was for this exact application. I have a couple of other threads about this and the JFET Cascode that should work.
The (output) coupling caps can be replaced with with 4.7uf Wimas. Some like the MKS2s because the leads have a 5mm spacing and they are better than the electrolytics but there is a better Wima choice, The MKP10 and try the Auricaps per Boky. I am also going to try the Obbligatos too.
The resistor right next to the coupling cap is a 10K, change it to a 100K (per Eric Juaneda). He also suggests losing the rest of the output stage after the coupling caps. I need to understand this mod more.
New wire from the PCB to better output RCA jacks. Boky suggests silver ribbosn (see his 94 MkII mod pics).
These are what I am going to do or I am already doing!
That should be enough to start with and I don't want to spend all your money but some say this unit can compete with $2000 and higher units.
Let me know! Also too bad you didn't get the RCD965, the PCB layout is better (one piece instead of two)!
Good luck and at least we can bounce ideas off each other as we move forward!
Regards//Keith
I am glad you got a chance to define what you were listeninng to. Now you know what it does well and what it does average. Although it is loaded with Blackgates, they aren't the end all. A lot has changed since the late 80s.
So what to do:
First cut out the Muting transistors. Noise and pops are next to nothing (I listen loud and it is no problem).
If you want to start with a decent Power cord and IEC Inlet with better wiring to the mains, I highly recommend it (although the hot passes through the switch and then a fuse). Places of degradation in my opinion.
These really benefit from Clean power so figure where you will get the best bang for the buck with the right caps and diodes and rectifiers (I haven't gotten there yet).
You might also choose additional power/regulators for a new clock and for the DAC. Another significant improvement in these. (Not there yet either).
Clock is paramount!
Better caps to decouple the DAC might help, maybe the other guys can assist on this.
My choice for new op amps was OPA627APs because they will add some warmth. There are some great ADxxx op amps that apply but although they are articulate and detailed, they are a little too cold for this CDP IMO (already a little cold). If you experiment, use sockets. I almost trashed my PCB soldering too much and op amps get expensive if you have to cut all of them out.
As far as Biasing to Class A, well some of the guys I respect most suggest not to but I may experiment just to satisfy my curiosity. So many and especially Carlosfm rave about this mod. Although I don't think it was for this exact application. I have a couple of other threads about this and the JFET Cascode that should work.
The (output) coupling caps can be replaced with with 4.7uf Wimas. Some like the MKS2s because the leads have a 5mm spacing and they are better than the electrolytics but there is a better Wima choice, The MKP10 and try the Auricaps per Boky. I am also going to try the Obbligatos too.
The resistor right next to the coupling cap is a 10K, change it to a 100K (per Eric Juaneda). He also suggests losing the rest of the output stage after the coupling caps. I need to understand this mod more.
New wire from the PCB to better output RCA jacks. Boky suggests silver ribbosn (see his 94 MkII mod pics).
These are what I am going to do or I am already doing!
That should be enough to start with and I don't want to spend all your money but some say this unit can compete with $2000 and higher units.
Let me know! Also too bad you didn't get the RCD965, the PCB layout is better (one piece instead of two)!
Good luck and at least we can bounce ideas off each other as we move forward!
Regards//Keith
Keith, Have you had a chance to compare ad847 and opa627? So far, I'm tested LM6171 and ad843, and prefer the latter.
No but my friend that works at Rotel USA as a Tech said mine sounded the best he has heard and they did many AD847s. I read many endorsements for the 627 here and on other web-sites. It is nice for the Rotel 865/965 especially if you want to warm up the sound a little.
Thanks for that roundup of mods Keith, it looks like a very good list, at least to begin with. I can't spend any money right now as I'm somewhat troubled by money (the lack of it).
I could do the op-amps and IEC socket without really spending anything. I have some OPA627bp (DIP), although they are soldered onto Browndog adapters so I'll need to carefully remove them. I'm also a fan of the 627, it was one of my favourites (but second to LM4562) in the CD63 before moving to discrete.
Of course it's cheap to sort out some proper feet and chassis damping (has a rings-like-a-bell lid) and to remove those muting transistors.
As for coupling caps, I won't need any as I have some in my pre-amp, which I'm about to upgrade to Black Gate AC (possibly some of the best around).
I expect the clock will prove to be the most important thing, but that will cost...
For today, this is nice stock, and I'm about to go and collect my main CD player from the "dry-dock"!
Great to see this discussion revived.
Simon
I could do the op-amps and IEC socket without really spending anything. I have some OPA627bp (DIP), although they are soldered onto Browndog adapters so I'll need to carefully remove them. I'm also a fan of the 627, it was one of my favourites (but second to LM4562) in the CD63 before moving to discrete.
Of course it's cheap to sort out some proper feet and chassis damping (has a rings-like-a-bell lid) and to remove those muting transistors.
As for coupling caps, I won't need any as I have some in my pre-amp, which I'm about to upgrade to Black Gate AC (possibly some of the best around).
I expect the clock will prove to be the most important thing, but that will cost...
For today, this is nice stock, and I'm about to go and collect my main CD player from the "dry-dock"!
Great to see this discussion revived.
Simon
Hi Simon,
You will hear a nice change with the OPA627s and no muting transistors. If you replace the Output Caps, please spend the 12 GBP (or maybe less) and get at least the Wima MKP10s 4.7uf. That will bring some more of the characteristics that you like in your modded Marantz (Boky said they make the SS CD Players bloom). Dampening is cheap and the feet too, so if you do just this list for a minimal investment, you will be quite pleased!
Order a new belt and pivot plate (2 GBP) for the Transport from Rotel and install them too.
Then look into cleaning up the PS, it shouldn't cost much either. Then listen for a while. You might find it sounds just fine without doing more until you have the gatos (money).
Hopefully, some of the guys with experience can shed some light on cost effective mods for the PS.
Careful with those 627s, they are almost impossible to find now. TI is saying no more until at least spring 2008. (I am looking for some too).
And if anybody has some better suggestions, they are welcome!
Regards//Keith
You will hear a nice change with the OPA627s and no muting transistors. If you replace the Output Caps, please spend the 12 GBP (or maybe less) and get at least the Wima MKP10s 4.7uf. That will bring some more of the characteristics that you like in your modded Marantz (Boky said they make the SS CD Players bloom). Dampening is cheap and the feet too, so if you do just this list for a minimal investment, you will be quite pleased!
Order a new belt and pivot plate (2 GBP) for the Transport from Rotel and install them too.
Then look into cleaning up the PS, it shouldn't cost much either. Then listen for a while. You might find it sounds just fine without doing more until you have the gatos (money).
Hopefully, some of the guys with experience can shed some light on cost effective mods for the PS.
Careful with those 627s, they are almost impossible to find now. TI is saying no more until at least spring 2008. (I am looking for some too).
And if anybody has some better suggestions, they are welcome!
Regards//Keith
Great tips Keith. I will be careful with my 627s.
We took another look inside the player today and it doesn't have op-amps in it. There are two spaces for op-amps (U401 & 402) but they're not filled. Also, some resistors are cut and some circuit appears to be bypassed (U108 & U301 are bypassed), and the DC blocking caps. It looks like the secondary pcb was an afterthought or an upgrade. The DAC is SAA7320.
Your service manual is for the "865BX", but mine is just "865", I wonder if this explains some of the differences.
Simon
We took another look inside the player today and it doesn't have op-amps in it. There are two spaces for op-amps (U401 & 402) but they're not filled. Also, some resistors are cut and some circuit appears to be bypassed (U108 & U301 are bypassed), and the DC blocking caps. It looks like the secondary pcb was an afterthought or an upgrade. The DAC is SAA7320.
Your service manual is for the "865BX", but mine is just "865", I wonder if this explains some of the differences.
Simon
Simon,
Yikes! What do you have? Now I know why you said what you did about the sound.
Contact Rotel directly, they are great with Customer Service and Technical Support. Maybe they can tell you what you have. Maybe the earliest version? Maybe someone else's Mod disaster? Maybe an imposter?
The two PCBs are what made me wonder. The 865s and 965s I have talked with others about, all have one. I have two 965s and it is just one. Also look at the schematics, there is no place where the wires jump from one board to the other so I wonder what you have.
Maybe it is a collector's item and Rotel is still looking for their missing prototype and will pay big bucks for it! (just a fantasy).
Find out what you can, I am curious!
That service manual is the only one Rotel has for this unit! So I wonder.
Regards//Keith
Yikes! What do you have? Now I know why you said what you did about the sound.
Contact Rotel directly, they are great with Customer Service and Technical Support. Maybe they can tell you what you have. Maybe the earliest version? Maybe someone else's Mod disaster? Maybe an imposter?
The two PCBs are what made me wonder. The 865s and 965s I have talked with others about, all have one. I have two 965s and it is just one. Also look at the schematics, there is no place where the wires jump from one board to the other so I wonder what you have.
Maybe it is a collector's item and Rotel is still looking for their missing prototype and will pay big bucks for it! (just a fantasy).
Find out what you can, I am curious!
That service manual is the only one Rotel has for this unit! So I wonder.
Regards//Keith
Keith,
When I get it back I'll take some well-lit macro shots to show you what's in there, but for now a friend is having a play with it, just for his own curiosity.
Clearly some parts aren't used in mine, and that is perhaps the most interesting thing. The riser board has plenty of polystyrene caps on it, which I guess are for filtering. The chassis has been drilled for the stand-offs and the holes appear to be factory drilled (very neat). This is definitely not a DIY job.
Where the audio leads come from the riser pcb to the main one is by the muting transistors (goes through nothing else). It looks easy to simply remove this connection and take that straight to the output jacks.
Brent has stripped the player down now so if there are any questions about parts etc... fire away.
Simon
When I get it back I'll take some well-lit macro shots to show you what's in there, but for now a friend is having a play with it, just for his own curiosity.
Clearly some parts aren't used in mine, and that is perhaps the most interesting thing. The riser board has plenty of polystyrene caps on it, which I guess are for filtering. The chassis has been drilled for the stand-offs and the holes appear to be factory drilled (very neat). This is definitely not a DIY job.
Where the audio leads come from the riser pcb to the main one is by the muting transistors (goes through nothing else). It looks easy to simply remove this connection and take that straight to the output jacks.
Brent has stripped the player down now so if there are any questions about parts etc... fire away.
Simon
Hi
I have Simons player here in bits, the stand off dac pcb is defo a factory built / rotel upgraded part. It looks designed for this application.
The original dac is removed and the extra pcb connects into various holes on the original dac placement.
After the onboard filter stage of hte extra pcb the audio goes to the muting transistors. The opamps and resistors have been bypassed.
I will take some pics tomorrow.
Brent
I have Simons player here in bits, the stand off dac pcb is defo a factory built / rotel upgraded part. It looks designed for this application.
The original dac is removed and the extra pcb connects into various holes on the original dac placement.
After the onboard filter stage of hte extra pcb the audio goes to the muting transistors. The opamps and resistors have been bypassed.
I will take some pics tomorrow.
Brent
Hi Simon and Brent,
Today I spoke with my friend at Rotel USA, and ha said he never heard of a RCD-865 (without the BX). Also there is nothing in Rotel USA's database either. What you have is a mystery!
Contact Rotel UK, they might have an idea. It also might be a Rotel UK Distributor modded product like the RCD-965BX Discrete.
See this thread, maybe "Tubenut" knows something about this too! http://www.diyaudio.com/forums/showthread.php?threadid=105387&highlight=
Let me know what you find! If you get some good pics I will send them to my friend and he can show some of the older guys at Rotel!
Regards//Keith
Today I spoke with my friend at Rotel USA, and ha said he never heard of a RCD-865 (without the BX). Also there is nothing in Rotel USA's database either. What you have is a mystery!
Contact Rotel UK, they might have an idea. It also might be a Rotel UK Distributor modded product like the RCD-965BX Discrete.
See this thread, maybe "Tubenut" knows something about this too! http://www.diyaudio.com/forums/showthread.php?threadid=105387&highlight=
Let me know what you find! If you get some good pics I will send them to my friend and he can show some of the older guys at Rotel!
Regards//Keith
Very interesting indeed.
I will take some pics on monday and i'm sure Simon will ring Rotel.
cheers
Brent
I will take some pics on monday and i'm sure Simon will ring Rotel.
cheers
Brent
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