Hi everyone, this is probably one for novice modders, like myself.
I decided to try wiring in bypass/additional caps in my amplifier's PSU (Roksan Caspian integrated). These caps were mostly spare/used and are:
-22nf/400v film x2
-8.2uf/400v metal film MKP x2
-180uf/200v x2
-330uf/200v x2
-470uf/200v x2
10 caps in all, about 2,000uf to add to the existing 13,600uf.
The sound:
First impressions are of a cleaner, more sterile sound, uninvolving but powerful.
After some hours of play the sound has warmed up a lot and has more solid and controlled bass than ever before.
Overall, [probably] positive, and free! (because the caps weren't otherwise used)
I am going to try adding 4x 10,000uf to really beef it up, and we'll see what that does for the bass...
-Simon
I decided to try wiring in bypass/additional caps in my amplifier's PSU (Roksan Caspian integrated). These caps were mostly spare/used and are:
-22nf/400v film x2
-8.2uf/400v metal film MKP x2
-180uf/200v x2
-330uf/200v x2
-470uf/200v x2
10 caps in all, about 2,000uf to add to the existing 13,600uf.
The sound:
First impressions are of a cleaner, more sterile sound, uninvolving but powerful.
After some hours of play the sound has warmed up a lot and has more solid and controlled bass than ever before.
Overall, [probably] positive, and free! (because the caps weren't otherwise used)
I am going to try adding 4x 10,000uf to really beef it up, and we'll see what that does for the bass...
-Simon
Testing with the first electrolytic cap. I put newspapers over the open amp and ducked down when turning it on, I get so scared of stuff blowing up or electrocuting me! 
I wired the caps in parallel with the original caps btw, one of each type per side. I must say, the reservoir caps seem to be wired in a funny way, it makes no sense to me! The + side of one is wired to the common ground - maybe someone technical can explain this phenomenon...
I wired the caps in parallel with the original caps btw, one of each type per side. I must say, the reservoir caps seem to be wired in a funny way, it makes no sense to me! The + side of one is wired to the common ground - maybe someone technical can explain this phenomenon...Attachments
Hello Analog Sa,
Instead of being so negative, why not try giving some advice or opinions?
Simonty, I do believe you probably heard a difference. When I parallel caps I have learned to keep the signal path as short as possible and I use only solid core wire inside my projects.
You might also try the 10% rule: You should not add a cap unless it is 10% the size or smaller than the cap you are paralelling.
Experimentation is everything. I would try adding the 8.2uf and 22nf caps first and then listen. You might like what you hear.
Also I have learned from other forum members (Peter Daniel & Peranders) that capacitor quality plays a more important part than sheer size or capacitance.
Good luck and keep us updated.
Cheers
KevinLee
Instead of being so negative, why not try giving some advice or opinions?
Simonty, I do believe you probably heard a difference. When I parallel caps I have learned to keep the signal path as short as possible and I use only solid core wire inside my projects.
You might also try the 10% rule: You should not add a cap unless it is 10% the size or smaller than the cap you are paralelling.
Experimentation is everything. I would try adding the 8.2uf and 22nf caps first and then listen. You might like what you hear.
Also I have learned from other forum members (Peter Daniel & Peranders) that capacitor quality plays a more important part than sheer size or capacitance.
Good luck and keep us updated.
Cheers
KevinLee
i would recommend changing the rectifier diodes too....
http://www.schuro.de/Daten/IR/hfa08tb60.pdf
or its bigger brother...
http://www.schuro.de/Daten/IR/hfa25pb60.pdf
http://www.schuro.de/Daten/IR/hfa08tb60.pdf
or its bigger brother...
http://www.schuro.de/Daten/IR/hfa25pb60.pdf
Thanks for all the advice, it's greatly appreciated. I was intitailly quite upset by ..sa's curt and dismissive remarks, it made me wonder if there was any point in posting here.
KevenLee: I tried the 8.2uf caps alone first, and I believe I heard some improvement (sweeter), I can't say if it was more or less improvement than after putting them all in together. I will bear in mind the 10% rule in the future... though it happens with most of them: 6,800uf>470uf>8uf>22nf. re: quality - I'd like to put BGs in, but for £100/cap or whatever they would be in a PSU, I can't afford/justify the cost!
Moamps: thanks for the diagram, I will have a closer look later, when I'm not at work
tbla: I'd considered what changing those diodes might do, what would it do? Can I assume they aren't good/Shottky diodes in place already? (I can't see those pdfs on this crap pc, again will look later)
I am ordering 4x10,000uf caps, as the cost isn't huge for Samwha 63v units. I initially got the urge to 'beef up' the psu because I felt this amp was always a little too reserved and soft at higher volumes. I guessed improving/enlargening the reservoir might add some welly - it worked for my sub's plate amp which I tried first...
Thanks for your time, and sorry about the pics, I realise I went ott, now that I am on quite a slow pc!!
-Simon
KevenLee: I tried the 8.2uf caps alone first, and I believe I heard some improvement (sweeter), I can't say if it was more or less improvement than after putting them all in together. I will bear in mind the 10% rule in the future... though it happens with most of them: 6,800uf>470uf>8uf>22nf. re: quality - I'd like to put BGs in, but for £100/cap or whatever they would be in a PSU, I can't afford/justify the cost!
Moamps: thanks for the diagram, I will have a closer look later, when I'm not at work
tbla: I'd considered what changing those diodes might do, what would it do? Can I assume they aren't good/Shottky diodes in place already? (I can't see those pdfs on this crap pc, again will look later)
I am ordering 4x10,000uf caps, as the cost isn't huge for Samwha 63v units. I initially got the urge to 'beef up' the psu because I felt this amp was always a little too reserved and soft at higher volumes. I guessed improving/enlargening the reservoir might add some welly - it worked for my sub's plate amp which I tried first...
Thanks for your time, and sorry about the pics, I realise I went ott, now that I am on quite a slow pc!!
-Simon
>>I was intitailly quite upset by ..sa's curt and dismissive remarks, it made me wonder if there was any point in posting here.
Please don't be upset. Sa's comments like that is not welcomed nor a norm on diyaudio. Sa just forgot that he used to be a beginner also. Usually people are very helpful here.
For your mod, just a few points:
1. keep your wires to the additional filtering caps as short as possible, and use solid-core thick wire.
2. Get yourself some Panasonic FA or FC 10000uF caps.
3. Next step you should look at the regulator (if any) and coupling caps in the signal path.
Have fun and enjoy.
P.S. Nice pictures BTW.
Please don't be upset. Sa's comments like that is not welcomed nor a norm on diyaudio. Sa just forgot that he used to be a beginner also. Usually people are very helpful here.
For your mod, just a few points:
1. keep your wires to the additional filtering caps as short as possible, and use solid-core thick wire.
2. Get yourself some Panasonic FA or FC 10000uF caps.
3. Next step you should look at the regulator (if any) and coupling caps in the signal path.
Have fun and enjoy.
P.S. Nice pictures BTW.
SimontY said:
SimontY, don't get upset. This is a place for people to exchange ideas and your post and picture did nothing but that.
While I do agree with analog_sa that the mod did not make a difference sonically, it is the fact that you tried that matters at the end of the day.
and I for one like to see more people trying and I can tell you that I enjoyed your pictures.
Of course i can explain the 'dismissive remarks', although there's hardly any need. Adding random types of capacitors to a finely tuned device like the Caspian is taking random shots in the dark with a very inaccurate gun. The Roksan folks have a good reputation for sound at a modest outlay and have definitely listened to dozens of caps before choosing the types which produce the best bang for the buck in that particular design. I would be hesitant to recommend cap replacements with even 'approved'' audiophile types, as even BGs and nice films (Multicaps, Hovlands etc) may change the sound balance in a less than musical way. Is it possible to improve upon a mid range good sounding amp? Certainly, but it will take a good set of ears, carefully auditioning each change, a lot of experience in what really makes for a positive and worthwhile change and a fairly good idea of what you're doing. Oh, and a circuit diagram or good understanding how the circuitry works is certainly beneficial. I would have had a less dismissive attitude if the original poster had at least taken the trouble to take the circuit diagram off the board, including bias currents, use of dc servo etc. Why do we need to see pictures of wire and caps? Is there anything actually being built? I would be more interested to see pics of Simon's pet dog.
I don't have a dog, but I will endeavour to post some pictures of my pet cat for you
Once again, thanks a lot for the help/support/advice.
ps-on the Caspian, IMHO it isn't so good that it can't be improved easily - common sense tells me so much, it's barely ahead of the much cheaper Kandy (more refined, but far less powerful sounding/and on paper).
Once again, thanks a lot for the help/support/advice.
ps-on the Caspian, IMHO it isn't so good that it can't be improved easily - common sense tells me so much, it's barely ahead of the much cheaper Kandy (more refined, but far less powerful sounding/and on paper).
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