Hi Bob,
I have two Rotels. One RCD-965BX and one RCD-965BX LE (Limited Edition). I am working on the 965BX right now. I like this unit! I think it can be an overachiever with the right mods.
New OPA627BPs where the 5534s were. AndrewT is helping with the Cap values to the rails around the op amps and the best way to tweak from the op amps to the Phono Jack.
I built 2 JFET Cascodes to try biasing to Class A but but haven't tried them yet. I have read that it can be nice but the guys here that are experienced say this isn't the place to do it!
I have learned a lot about the coupling caps here and will lose the 100uf electrolytics and replace them with 4.7uf Wima MKP10s or Obbligato Film/Oil caps and maybe bypass them with the VR MKP1837s 0.01uf. Daves trials have helped me with those decisions.
Glad to hear the appendages problem is finally somewhere useful! NOW just THINK what you can THINK of with all that extra blood going someplace useful! YIKES! Now the true genius can come out! LOL
Dreamwork!!!!!!
Regards//Keith
I have two Rotels. One RCD-965BX and one RCD-965BX LE (Limited Edition). I am working on the 965BX right now. I like this unit! I think it can be an overachiever with the right mods.
New OPA627BPs where the 5534s were. AndrewT is helping with the Cap values to the rails around the op amps and the best way to tweak from the op amps to the Phono Jack.
I built 2 JFET Cascodes to try biasing to Class A but but haven't tried them yet. I have read that it can be nice but the guys here that are experienced say this isn't the place to do it!
I have learned a lot about the coupling caps here and will lose the 100uf electrolytics and replace them with 4.7uf Wima MKP10s or Obbligato Film/Oil caps and maybe bypass them with the VR MKP1837s 0.01uf. Daves trials have helped me with those decisions.
Glad to hear the appendages problem is finally somewhere useful! NOW just THINK what you can THINK of with all that extra blood going someplace useful! YIKES! Now the true genius can come out! LOL
Dreamwork!!!!!!
Regards//Keith
Hi Keith,
IIRC those were quite good CD players, and I was once asked to do some improvements to one of them.
This was quite a while ago, and again IIRC, it was mainly connected more with the analogue side like output coupling caps & op-amps etc. Somewhere in my archives I still have the service manual which I will have a look at once more, in the fullness of time, and see if I can recall more precisely what I did to it.
I don't wish to step on anyones' toes though, all the while things are going well.
As for the rush of blood to the head, I do go quite giddy sometimes, but I always assumed it was the drink. Still I do make a few mistakes from time-to-time.
Regards,
IIRC those were quite good CD players, and I was once asked to do some improvements to one of them.
This was quite a while ago, and again IIRC, it was mainly connected more with the analogue side like output coupling caps & op-amps etc. Somewhere in my archives I still have the service manual which I will have a look at once more, in the fullness of time, and see if I can recall more precisely what I did to it.
I don't wish to step on anyones' toes though, all the while things are going well.
As for the rush of blood to the head, I do go quite giddy sometimes, but I always assumed it was the drink. Still I do make a few mistakes from time-to-time.
Regards,
Hi Bob,
I would love to hear what you did on that Rotel. But I don't want to go OT that far.
If you would like to compare notes, please feel free to send me a PM so we can let this thread stay on track here. Maybe you have some experience with op amp biasing, that would be very helpful for me to make and understand any decision about whether to go forward with it.
Regards//Keith
I would love to hear what you did on that Rotel. But I don't want to go OT that far.
If you would like to compare notes, please feel free to send me a PM so we can let this thread stay on track here. Maybe you have some experience with op amp biasing, that would be very helpful for me to make and understand any decision about whether to go forward with it.
Regards//Keith
I'm not sure why I did this, but I tried the Obbligato PIO (2.0uf) and the MKT1822 (2.2uf) and the MKP1837 (0.01uf) caps together. It's an interesting combo. The depth of the soundstage seemed to have increased beyond what either the Obbligato or MKT1822 could do alone with a bypass. I'm really not sure what to think of this result. The tone seems a little off, and the depth may be artificially created by the interaction of the two caps. Overall, though, it's very listenable. Anyone have any thoughts or experiences in running caps of similar values together? It seems like an odd idea.
Hi Dweekie,
I had asked about this a while back about cutting the desired value in half and reversing the second cap. Funny but Curmudgeon said it worked for him although it was 10 caps with 5 in each direction.
Maybe some were thinking I was nuts but this is where we will find some future innovations, by doing the unexpected. I would guess the expected has already been beaten to death anyway. So we will have a third phase to this thread..... Crazy Combinations with Input Caps! LOL..........Hey, but you never know!
Then we will have to bi-directionally bypass too! YIKES!
Regards//Keith
Curmudgeon said:
I had asked about this a while back about cutting the desired value in half and reversing the second cap. Funny but Curmudgeon said it worked for him although it was 10 caps with 5 in each direction.
Maybe some were thinking I was nuts but this is where we will find some future innovations, by doing the unexpected. I would guess the expected has already been beaten to death anyway. So we will have a third phase to this thread..... Crazy Combinations with Input Caps! LOL..........Hey, but you never know!
Then we will have to bi-directionally bypass too! YIKES!
Regards//Keith
The reversal idea may not be universally applicable. The Crescendoes were deliberately designed to be directional, to allow a choice of coloration preference. Since one was warmer, the other colder, it was no great leap to try canceling. I was surprised that it worked, let alone as well as it did.
The situation was unusual in that the Crescendos did not suffer from harshness, just tonal balance. Harshness/grain/whatever is the most common cap problem from what we've tried and I doubt very much that the anti-parallel idea would help that.
I do miss the North Creek caps; they were very good value I thought. I hope someone buys that portion of the business...
The situation was unusual in that the Crescendos did not suffer from harshness, just tonal balance. Harshness/grain/whatever is the most common cap problem from what we've tried and I doubt very much that the anti-parallel idea would help that.
I do miss the North Creek caps; they were very good value I thought. I hope someone buys that portion of the business...
Interim Test Observations
I did a simple comparison of three different 0.1 μf capacitors in the bypass position of a Blackgate electrolytic. In parallel to the 0.1
μf cap there was a 0.01 μf WIMA film and 30 pf silver mica cap.
I switched between the Flourinert, Film, and Russian Teflon cap. The film cap yielded a "plumper" bass. The Fourinert sounded a little more accurate than the Teflon. This is a subjective observation. The Flourinert sounded the best of the three. The film sounded a fuller and somewhat slower.
The flourinert also made the sound somewhat darker and the soundstage deeper. I will perform a removal of bypass caps from the above to try to isolate what each cap contributes.
I have also received a ton of caps from one reader. The caps from readers are next up for testing. Despite my intuitive sense regarding bypass caps and warnings from Bob I will press on with the testing.
I did a simple comparison of three different 0.1 μf capacitors in the bypass position of a Blackgate electrolytic. In parallel to the 0.1
μf cap there was a 0.01 μf WIMA film and 30 pf silver mica cap.
I switched between the Flourinert, Film, and Russian Teflon cap. The film cap yielded a "plumper" bass. The Fourinert sounded a little more accurate than the Teflon. This is a subjective observation. The Flourinert sounded the best of the three. The film sounded a fuller and somewhat slower.
The flourinert also made the sound somewhat darker and the soundstage deeper. I will perform a removal of bypass caps from the above to try to isolate what each cap contributes.
I have also received a ton of caps from one reader. The caps from readers are next up for testing. Despite my intuitive sense regarding bypass caps and warnings from Bob I will press on with the testing.
Re: Interim Test Observations
Hi Dave,
I sincerely hope that you do press on with these trials and that you ultimately end up with a fine result.
As I have tried to impress all along, the experiences I have shared are generalisations and are therefore only guidelines, and there are no definitve answers in this game. The great thing is that you can readily hear and describe these differences, but if you had merely listened to some (the majority!) of the louder posters on this Forum, you would probably have never reached this stage.
Whatever happens, I am sure that you will learn a lot more about this subject, and that you will not regret any of the time you spend.
Good luck with your efforts, and I will watch this thread with interest to hear about some more of your results.
Regards,
Davet said:
Hi Dave,
I sincerely hope that you do press on with these trials and that you ultimately end up with a fine result.
As I have tried to impress all along, the experiences I have shared are generalisations and are therefore only guidelines, and there are no definitve answers in this game. The great thing is that you can readily hear and describe these differences, but if you had merely listened to some (the majority!) of the louder posters on this Forum, you would probably have never reached this stage.
Whatever happens, I am sure that you will learn a lot more about this subject, and that you will not regret any of the time you spend.
Good luck with your efforts, and I will watch this thread with interest to hear about some more of your results.
Regards,
KP11520 said:
Hi Keith,
Absolutely, and why not?
Anything goes here, and it will make a difference as I am quite confident. Whether it will be an improvement in one or more locatons where this configuration is tried is another matter, and only careful listening trials will determine this.
There is certainly a noticeable sonic difference when comparing the BG 'Super E' configuration, where one identical cap is 'reversed' compared with its partner in a specific location, if this is also tried with the same 2 caps which are installed in the same direction.
Regards,
Hi Dave, Keith, Bob & others..
Having read a post on another subject by "danielwritesbac" on the ESR of caps, I wonder if it has any relevance here?
What he seems to be saying is that polyester and polystyrene are at opposite ends of the ESR scale.
Yet in this location, they can sound very similar, any thoughts? More effect when bypassing perhaps?
Or just a lot of irrelevant nonsense?
Question everything..
Regards,
Having read a post on another subject by "danielwritesbac" on the ESR of caps, I wonder if it has any relevance here?
What he seems to be saying is that polyester and polystyrene are at opposite ends of the ESR scale.
Yet in this location, they can sound very similar, any thoughts? More effect when bypassing perhaps?
Or just a lot of irrelevant nonsense?
Question everything..
Regards,
Paper-in-oils??
Dear Bob
I wonder what is your view on the paper-in-oil caps especially newer Audionote ones, when used as a coupling cap. I know with Jensen(previous suppliers of AN caps) etc there were problems including leakage, deformation etc.
I know there was a 21 cap shootout published which put teflon V-caps right near the top, close behind the audionote silver PIOs, which are many times the price. However, I wonder how do AN copper PIOs (whose dielectric will be same as the top-ranked silver caps) would fare compared to v-caps, as you say your ranking order concided with the DA of the cap.
Best regards
Bobken said:
Dear Bob
I wonder what is your view on the paper-in-oil caps especially newer Audionote ones, when used as a coupling cap. I know with Jensen(previous suppliers of AN caps) etc there were problems including leakage, deformation etc.
I know there was a 21 cap shootout published which put teflon V-caps right near the top, close behind the audionote silver PIOs, which are many times the price. However, I wonder how do AN copper PIOs (whose dielectric will be same as the top-ranked silver caps) would fare compared to v-caps, as you say your ranking order concided with the DA of the cap.
Best regards
Hi FibCouple,
This is one question related to caps which I simply don't know the answer to, I am sorry to say, as I haven't had the chance to compare any such recently-made caps.
It is a long while since I 'listened' to any of these caps, and when I previously had some PIO caps on trials I wasn't very impressed with the results. Also, as you mentioned, the longer-term performance of the earlier types was not very promising in view of their deterioration, and when I last contacted Audio Note UK a couple or so years ago as an OEM user, they declined to respond to me!
I believe since then they have stopped supplying others in the UK (from what I heard), although there is a US distributor who apparently took over the A.N. kit sales according to one of my associates. Possibly some dealers like PartsConneXion in Canada obtain their stocks through them, but I have not enquired any further about this.
I usually don't do much guessing, as I am often wrong when I do (!), but when comparing copper with silver in wires and connectors etc., I have a distinct preference for the silver types whenever this has been in a fair (and direct) comparison.
Accordingly, I would *guess* that there will be quite a sonic difference between these AN caps, as is also doubtlessly reflected in their relevant costs, but this is not based on any facts known to me.
Incidentally, whilst I was pleased to subsequently discover a clear relationship between some measurements and what my ears had told me a long while ago (and this often happens in other areas when one finally appreciates what is relevant to measure) I wouldn't suggest that DA is the only factor here. There are many other influences at work affecting the sonic results including the type of construction, the care in manufacture, and the quality of materials used etc. I know 'from the horse's mouth' that certain cap manufacturers purchase substandard 'packaging-quality' polypropylene film for use in their caps (instead of that made expressly for electronics) to save on costs, and this will not be good for ultimate sonics, even if they measure much the same.
Regards,
This is one question related to caps which I simply don't know the answer to, I am sorry to say, as I haven't had the chance to compare any such recently-made caps.
It is a long while since I 'listened' to any of these caps, and when I previously had some PIO caps on trials I wasn't very impressed with the results. Also, as you mentioned, the longer-term performance of the earlier types was not very promising in view of their deterioration, and when I last contacted Audio Note UK a couple or so years ago as an OEM user, they declined to respond to me!
I believe since then they have stopped supplying others in the UK (from what I heard), although there is a US distributor who apparently took over the A.N. kit sales according to one of my associates. Possibly some dealers like PartsConneXion in Canada obtain their stocks through them, but I have not enquired any further about this.
I usually don't do much guessing, as I am often wrong when I do (!), but when comparing copper with silver in wires and connectors etc., I have a distinct preference for the silver types whenever this has been in a fair (and direct) comparison.
Accordingly, I would *guess* that there will be quite a sonic difference between these AN caps, as is also doubtlessly reflected in their relevant costs, but this is not based on any facts known to me.
Incidentally, whilst I was pleased to subsequently discover a clear relationship between some measurements and what my ears had told me a long while ago (and this often happens in other areas when one finally appreciates what is relevant to measure) I wouldn't suggest that DA is the only factor here. There are many other influences at work affecting the sonic results including the type of construction, the care in manufacture, and the quality of materials used etc. I know 'from the horse's mouth' that certain cap manufacturers purchase substandard 'packaging-quality' polypropylene film for use in their caps (instead of that made expressly for electronics) to save on costs, and this will not be good for ultimate sonics, even if they measure much the same.
Regards,
audio1st said:
Hi,
Unfortunately, I didn't get very far with understanding quite a lot of what appeared in that thread, when I had a quick look at it after seeing this query, so I gave up with it.
Right from the first sentence I simply don't know what was meant by the term used "harmful effects". Later on, the comments appeared to me to be posed as riddles, but maybe I am just getting too old for such 'challenges'.
Does "harmful effects" refer to oscillation killing output TRs, or maybe a slight change in overall subjective results, or anywhere between these two extremes? I really have no idea, and so cannot sensibly pass any worthwhile comments in this instance.
A lot of SS amps will have a small cap across their outputs, albeit in series with a suitable resistor to form a Zobel network, to properly load these amps at HF and to maintain stability. This helps to avoid destructive oscillations, but in my experience will always have some (and not always welcome!) sonic affect on the perceived results. So, on one hand this will presumably be seen as a benefit, but as a "harmful effect" on the other.
Regards,
One of the more exacting applications is the series tweeter capacitor.
Sonically, the best capacitor we've found that we could afford was the Multicap tin foil/polystyrene, cleaner and more transparent than the polypropylene/tin foil, which was next best.
So sonically, I'd put the polystyrene furthest from the mylar/polyester/polythene, noting that we haven't tried teflon.
PS; and noting also that "best capacitors" for the higher current, higher voltage swing, crossover application may not be the same as those best suited to the high impedance/low current applications.
Sonically, the best capacitor we've found that we could afford was the Multicap tin foil/polystyrene, cleaner and more transparent than the polypropylene/tin foil, which was next best.
So sonically, I'd put the polystyrene furthest from the mylar/polyester/polythene, noting that we haven't tried teflon.
PS; and noting also that "best capacitors" for the higher current, higher voltage swing, crossover application may not be the same as those best suited to the high impedance/low current applications.
Silver Micas removed
I apologize for my prolonged silence. I damaged the test bed briefly and had to diagnose what the problem was. Fuse blew while system was sitting idle. No one eles was in the house. Problem still undetermined.. I replaced the power fuse and pressed on.
In addition, we have been undergoing some home renovations. With the pounding of hammers, drone of air compressors and the like it has been hard to listen of late. Hopefully, the contractors will be damn near finished early next week.
However I did get a short session in last night. I disconnected the 30 pf silver mica from the Bypassed Blackgate caps. What was immediately apparent to me was the striking of cymbals. With the silver mica in the circuit it sounded as if the drummer was in the room. The sensation I associate with that initial strike of the stick to the cymbal was gone. with the silver micas removed
So there is some sonic information being passed by the silver mica cap.
I apologize for my prolonged silence. I damaged the test bed briefly and had to diagnose what the problem was. Fuse blew while system was sitting idle. No one eles was in the house. Problem still undetermined.. I replaced the power fuse and pressed on.
In addition, we have been undergoing some home renovations. With the pounding of hammers, drone of air compressors and the like it has been hard to listen of late. Hopefully, the contractors will be damn near finished early next week.
However I did get a short session in last night. I disconnected the 30 pf silver mica from the Bypassed Blackgate caps. What was immediately apparent to me was the striking of cymbals. With the silver mica in the circuit it sounded as if the drummer was in the room. The sensation I associate with that initial strike of the stick to the cymbal was gone. with the silver micas removed
So there is some sonic information being passed by the silver mica cap.
Dave,
Nothing to worry about.... It was probably just the contractors BLASTING your system while you and your wife weren't home.
Hopefully, you will be back on track soon!
Also send or post a pic of the area in the amp where the input cap goes please. I get better ideas with a visual of what you have to work with.
Bob, I would still like to chat about what you did with that Rotel CD Player.
Regards to All,
Keith
Nothing to worry about.... It was probably just the contractors BLASTING your system while you and your wife weren't home.
Hopefully, you will be back on track soon!
Also send or post a pic of the area in the amp where the input cap goes please. I get better ideas with a visual of what you have to work with.
Bob, I would still like to chat about what you did with that Rotel CD Player.
Regards to All,
Keith
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.