Hi,
I have recently replaced the coupling caps on my A400 with Audyn MKP QS, which were quite a large component to fit on the amp but luckily there was space at their location. (C201/C202).
Replacing them brought about a warmer sound with a fuller bass, but I'm now wondering whether they were the best choice within a reasonable size and price. I later replaced many of the other caps with Black Gates and was wondering whether replacing the Audyn with high quality black gates i.e. N or NX range, would be a better choice as I am suspecting that these Audyns may be slowing the sound down.
Any ideas ?
I have recently replaced the coupling caps on my A400 with Audyn MKP QS, which were quite a large component to fit on the amp but luckily there was space at their location. (C201/C202).
Replacing them brought about a warmer sound with a fuller bass, but I'm now wondering whether they were the best choice within a reasonable size and price. I later replaced many of the other caps with Black Gates and was wondering whether replacing the Audyn with high quality black gates i.e. N or NX range, would be a better choice as I am suspecting that these Audyns may be slowing the sound down.
Any ideas ?
I guess that you're talking about the input capacitors 
You should've shown a schematic part. You can leave those in, I'd also go for quality electrolytics (Panasonic FC series will do in the large values needed) in the feedback loop unless you haven't done so.
To get an idea of how the caps sound leave them for a couple of days, make a 'test' track list from your cds, listen, then change the caps and listen to the same music through the new caps. Also leave them in for a couple of days so you can have a good idea on the performance.
You should've shown a schematic part. You can leave those in, I'd also go for quality electrolytics (Panasonic FC series will do in the large values needed) in the feedback loop unless you haven't done so.To get an idea of how the caps sound leave them for a couple of days, make a 'test' track list from your cds, listen, then change the caps and listen to the same music through the new caps. Also leave them in for a couple of days so you can have a good idea on the performance.
In my opinion, the Audyn MKP QS caps added greater bass depth and warmth but also blurred details, resulting in a less sharp sound.
Well I've gone ahead and replaced them with Black Gate Type C.
The sound already is more detailed and transparent with greater attack. Obviously the parts are still running in, so will have to wait and see how they improve.
Well I've gone ahead and replaced them with Black Gate Type C.
The sound already is more detailed and transparent with greater attack. Obviously the parts are still running in, so will have to wait and see how they improve.
Compared to how it sounded before the modifications, the amp now sounds more dynamic and detailed with less of the cold 'colourless' sound it was sometimes accused of. Though to be honest most of this 'colourless' sound was removed when I replaced the original main 2 Elna PSU caps with Panasonics, which due to the age of the amp probably weren't doing their job well anyway.
Included the coupling caps, I have replaced 9 of the caps per channel with Black Gates (18 in total), added some internal copper shielding, RF clamps and a new mains cable, all contributing to a much better sound.
So anyone who is wondering whether to replace theirs with Black Gates, the answer is a clear 'yes'!
P.S. Before this amp I owned a NAD C370 which amazingly the Pioneer walked all over.
Included the coupling caps, I have replaced 9 of the caps per channel with Black Gates (18 in total), added some internal copper shielding, RF clamps and a new mains cable, all contributing to a much better sound.
So anyone who is wondering whether to replace theirs with Black Gates, the answer is a clear 'yes'!
P.S. Before this amp I owned a NAD C370 which amazingly the Pioneer walked all over.
Hi,
There are some threads on here that list where you can get the schematics from. Unfortunately as you can't attach files here, I can't provide them, however naturally the corresponding part positions below are marked on the PCB.
Revealed for the first time are my modifications below ! :
C201/C202 (coupling cap) : Rubycon Black Gate Type C 2.2uF 50v
C212/C212 : Rubycon Black Gate Standard 220 16v
C301/C302 : Rubycon Black Gate Type C 2.2uF 50v
C220/C225 (check!): Rubycon Black Gate Standard 330uF 16v (Original was 10v)
C237/C238 : Rubycon Black Gate Standard 100uF 50v
C235/C236 : Rubycon Black Gate Standard 10uF 50v
C217/C218 : Rubycon Black Gate Standard 100uF 16v (Original was 10v)
C219/C220 : Rubycon Black Gate Standard 3.3uF 250v (Original was 100v)
C221/C222 : Rubycon Black Gate Standard 3.3uF 250v (Original was 100v)
C233/C234 : Rubycon Black Gate Standard 10uF 50v
All replacements correspond to ratings (excluding dimensions) of original parts unless otherwise stated
Other changes – Increase of bias current to approx 180 mA (60mV?) - (similar to an A400GTE mod done by by Tom Evans)
Mains cable addition – Audusa CSA with silver plated MK ToughPlug
RF clamps to internal mains cables where possible
Elna PSU Smoothing caps (10,000 uF 50v) replaced with Panasonic TSUP.
C306 (next to PSU smoothing caps) also replaced with Jelmax Black Gate NX HiQ 0.47 uF 50v.
Blue power LED !
BluTak damping
Internal copper shielding round PSU and certain other places with copper shielding tape.
Hope all A400 'modders' find this helpful
Dav
There are some threads on here that list where you can get the schematics from. Unfortunately as you can't attach files here, I can't provide them, however naturally the corresponding part positions below are marked on the PCB.
Revealed for the first time are my modifications below ! :
C201/C202 (coupling cap) : Rubycon Black Gate Type C 2.2uF 50v
C212/C212 : Rubycon Black Gate Standard 220 16v
C301/C302 : Rubycon Black Gate Type C 2.2uF 50v
C220/C225 (check!): Rubycon Black Gate Standard 330uF 16v (Original was 10v)
C237/C238 : Rubycon Black Gate Standard 100uF 50v
C235/C236 : Rubycon Black Gate Standard 10uF 50v
C217/C218 : Rubycon Black Gate Standard 100uF 16v (Original was 10v)
C219/C220 : Rubycon Black Gate Standard 3.3uF 250v (Original was 100v)
C221/C222 : Rubycon Black Gate Standard 3.3uF 250v (Original was 100v)
C233/C234 : Rubycon Black Gate Standard 10uF 50v
All replacements correspond to ratings (excluding dimensions) of original parts unless otherwise stated
Other changes – Increase of bias current to approx 180 mA (60mV?) - (similar to an A400GTE mod done by by Tom Evans)
Mains cable addition – Audusa CSA with silver plated MK ToughPlug
RF clamps to internal mains cables where possible
Elna PSU Smoothing caps (10,000 uF 50v) replaced with Panasonic TSUP.
C306 (next to PSU smoothing caps) also replaced with Jelmax Black Gate NX HiQ 0.47 uF 50v.
Blue power LED !
BluTak damping
Internal copper shielding round PSU and certain other places with copper shielding tape.
Hope all A400 'modders' find this helpful
Dav
Mudan, your a star, ive done plenty to the CD63KI not even finsihed with that yet, now i will book the A400 into the operating theatre ! lol
ill start on some of the mods at the weekend, need to place some orders really, i have some wilmas for under the smoothing caps, have lots of copper sheilding tape and some very nice silver military cable just arrived. I have an iec socket to go on so ill do all mains cables and the iec in one hit. Ive already damped the case and chassis.
I really need to get the volume pot sorted as im getting more sensitive to the crackling, cos its duel gang im not sure who supplies one. I may see if i can just use an alps single shaft and do away with the balance ???? i just dont like losing the balance.
If you get the chance post some pics.
Thanks again for the list, ive seem the schematics on here but was on works laptop at time and the download was blockewd by our it department lol.
ill start on some of the mods at the weekend, need to place some orders really, i have some wilmas for under the smoothing caps, have lots of copper sheilding tape and some very nice silver military cable just arrived. I have an iec socket to go on so ill do all mains cables and the iec in one hit. Ive already damped the case and chassis.
I really need to get the volume pot sorted as im getting more sensitive to the crackling, cos its duel gang im not sure who supplies one. I may see if i can just use an alps single shaft and do away with the balance ???? i just dont like losing the balance.
If you get the chance post some pics.
Thanks again for the list, ive seem the schematics on here but was on works laptop at time and the download was blockewd by our it department lol.
Leolabs, the Audyns were used as coupling caps. I don't have their specs to hand, but the ones that replaced them were:
Rubycon Black Gate Type C 2.2uF 50v
Imsparticus, I also had to replace the volume pot which I ordered the same as the original from a company based in Leicester. I think they are called SEMA but I may be totally wrong! - if you do a search on here, I'm sure you'll find them.
Rather than fitting an IEC socket, which obviously is the tidier way, I cut the original cable just outside the casing and used a sealed connector box. Some go as far as soldering the better quality cable all the way inside to the switch/pcb.
Rubycon Black Gate Type C 2.2uF 50v
Imsparticus, I also had to replace the volume pot which I ordered the same as the original from a company based in Leicester. I think they are called SEMA but I may be totally wrong!
- if you do a search on here, I'm sure you'll find them.Rather than fitting an IEC socket, which obviously is the tidier way, I cut the original cable just outside the casing and used a sealed connector box. Some go as far as soldering the better quality cable all the way inside to the switch/pcb.
Hi, that's right - it is SEME - I have a CD catalogue at home.
At work at the moment, so couldn't check.
The best option would be to put the mains cable directly soldered, however it looked a too messy or tricky job for me so stuck to the connector box. A smarter option is the IEC socket but I didn't want to cut into the metal casing at the time, though I may change over to this option.
In the connector box, the amp's orginal and the Audusa cable overlap each other under pressure so that's the best connection at the moment, though being the way mains noise reduction works, I doubt if adding an IEC socket and plug in between would degrade the performance much.
At work at the moment, so couldn't check.
The best option would be to put the mains cable directly soldered, however it looked a too messy or tricky job for me so stuck to the connector box. A smarter option is the IEC socket but I didn't want to cut into the metal casing at the time, though I may change over to this option.
In the connector box, the amp's orginal and the Audusa cable overlap each other under pressure so that's the best connection at the moment, though being the way mains noise reduction works, I doubt if adding an IEC socket and plug in between would degrade the performance much.
I found a new website which lists the schematics.
See:
http://www.hifiengine.com/library_model.php?make=Pioneer&selected_model=A400
See:
http://www.hifiengine.com/library_model.php?make=Pioneer&selected_model=A400
mudan, thanks m8, that was the site i had seen but not allowed to download to the works laptop lol, im just putting the pages together now.
I have some Blackgate non polar coupling caps bypassed in the CD63, sure they were 100uf tho ? i will try them after removing them, not sure what you think ? To be honest, they should be fine as they decouple the same output that the amp input will receive.
I will see if i get anything done this afternoon, been so busy with xmas on its way.
dennis
I have some Blackgate non polar coupling caps bypassed in the CD63, sure they were 100uf tho ? i will try them after removing them, not sure what you think ? To be honest, they should be fine as they decouple the same output that the amp input will receive.
I will see if i get anything done this afternoon, been so busy with xmas on its way.
dennis
I have heard that if the Elna PSU caps are near the end of their life (i.e. possibly dried up), they can make the amp emit a buzzing/humming sound.
This was not the case for my A400, however thought that replacing them, due to their age and importance would bring about an improvement and thankfully, it did. They removed the cold and clinical sound the A400 is sometime accused of. At first I was concerned about their neutrality, thinking that despite the extra detail and 'warmth' offered they may have coloured the sound. However I can positively say that they make an improvement and quite a significant one too.
This was not the case for my A400, however thought that replacing them, due to their age and importance would bring about an improvement and thankfully, it did. They removed the cold and clinical sound the A400 is sometime accused of. At first I was concerned about their neutrality, thinking that despite the extra detail and 'warmth' offered they may have coloured the sound. However I can positively say that they make an improvement and quite a significant one too.
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