Ok.
C1 is the only bipolar ... 47 mfd, 16v
C2 ... 100uf, 25v (probably go 50v)
C4-5 ... 100uF, 100v
I need to see what options will work for the ps caps. I don't need boutique here. As good as the amp sounds now, I'm fine with a comparable quality option that has the higher rating and fits.
I do need to select Bourns trimmers with side adjust, single turn are fine, but I'm open to multi turn. Not sure if that is needed. All I know about the stock trimmers is they are 500 ohm.
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Yes, thanks. For some reason, my meter wants to read .500 k Ohms instead of ohms. Good catch!
Ok, here's my parts list with links to Mouser. I'm not 100% on the Bourns trimmers, so feel free to offer a better suggestion, if you have time. I do appreciate your help guys!!
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Trimmers
Bourns 3/8" through hole 500 ohm horiz adjust 3296P-1-501LF Bourns | Mouser
Electrolytic capacitors
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C1 47uF, 16v NP
Nichicon 47uF, 25v UES1E470MPM Nichicon | Mouser
or
Nichicon 47uF, 35v UES1V470MPM Nichicon | Mouser
C2 100uF, 50v (was 25v)
Nichicon KZ UKZ1H101MHM Nichicon | Mouser
C4,C5 100uF, 100v
Nichicon KZ https://www.mouser.com/ProductDetail/647-UKZ2A101MHM
KC ... you mentioned I should have an 8A fuse (125v or 250v) at the AC holder on the back panel. I can't find any, and when searching Mouser, only find ceramic versions. Do you mind suggesting a fuse that will work? Thanks.
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Trimmers
Bourns 3/8" through hole 500 ohm horiz adjust 3296P-1-501LF Bourns | Mouser
Electrolytic capacitors
---------------------------
C1 47uF, 16v NP
Nichicon 47uF, 25v UES1E470MPM Nichicon | Mouser
or
Nichicon 47uF, 35v UES1V470MPM Nichicon | Mouser
C2 100uF, 50v (was 25v)
Nichicon KZ UKZ1H101MHM Nichicon | Mouser
C4,C5 100uF, 100v
Nichicon KZ https://www.mouser.com/ProductDetail/647-UKZ2A101MHM
KC ... you mentioned I should have an 8A fuse (125v or 250v) at the AC holder on the back panel. I can't find any, and when searching Mouser, only find ceramic versions. Do you mind suggesting a fuse that will work? Thanks.
Ok, I made some changes on the parts list (post #1) that I can't change on my previous post #304. Here's what I think my final order will be. I just have to choose between power supply cap uF value, and the bipolar cap (25v or 35v rating, when stock is 16v).
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Trimmers
Bourns 3266P 1/4" through hole 500 ohm horiz adjust 3266P-1-501LF Bourns | Mouser
Electrolytic capacitors
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Power Supply Caps (22mm or 32mm lead spacing required)
KEMET has the only two options with correct lead spacing, and similar dimensions. I can go smaller diameter, but would have to source a smaller holder that will mount into the chassis. I'd prefer to not have to drill holes.
Both have 100v rating and cost about the same, $23/each ... however, the smaller uF cap has a higher temp rating at 105C, vs the larger uF having 85C.
16,000uF ALS80A163KF100 KEMET | Mouser
20,000uF ALS70A203KF100 KEMET | Mouser
C1 47uF, 16v NP
Nichicon 47uF, 25v UES1E470MPM Nichicon | Mouser
or
Nichicon 47uF, 35v UES1V470MPM Nichicon | Mouser
C2 100uF, 50v (was 25v)
Nichicon KZ UKZ1H101MHM Nichicon | Mouser
C4,C5 100uF, 100v
Nichicon KZ UKZ2A101MHM Nichicon | Mouser
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Trimmers
Bourns 3266P 1/4" through hole 500 ohm horiz adjust 3266P-1-501LF Bourns | Mouser
Electrolytic capacitors
---------------------------
Power Supply Caps (22mm or 32mm lead spacing required)
KEMET has the only two options with correct lead spacing, and similar dimensions. I can go smaller diameter, but would have to source a smaller holder that will mount into the chassis. I'd prefer to not have to drill holes.
Both have 100v rating and cost about the same, $23/each ... however, the smaller uF cap has a higher temp rating at 105C, vs the larger uF having 85C.
16,000uF ALS80A163KF100 KEMET | Mouser
20,000uF ALS70A203KF100 KEMET | Mouser
C1 47uF, 16v NP
Nichicon 47uF, 25v UES1E470MPM Nichicon | Mouser
or
Nichicon 47uF, 35v UES1V470MPM Nichicon | Mouser
C2 100uF, 50v (was 25v)
Nichicon KZ UKZ1H101MHM Nichicon | Mouser
C4,C5 100uF, 100v
Nichicon KZ UKZ2A101MHM Nichicon | Mouser
The nichicon kz are great parts.
If the C2 part is passing signal, I would tend to go with the 25v part. I have found that often the lower esr associated with a higher voltage part can add harshness. If it’s a power supply, then the higher voltage rating won’t hurt.
If you can’t fit a good 4.7uf film cap for C1, try and see if a .22uf Wima mkp10 can be used as a bypass possibly if there’s any room for that.
If the C2 part is passing signal, I would tend to go with the 25v part. I have found that often the lower esr associated with a higher voltage part can add harshness. If it’s a power supply, then the higher voltage rating won’t hurt.
If you can’t fit a good 4.7uf film cap for C1, try and see if a .22uf Wima mkp10 can be used as a bypass possibly if there’s any room for that.
I have about 1.125" of space between top of pcb and back of chassis to put a film cap ... this allows for about 3/8" of space. I could use this Mundorf MKP:
Mundorf Capacitor 4.70uF 250Vdc MCap® Classic (MKP)
I like Nichicon Muse. Use it whenever possible.
I don't know if C2 is passing signal, but since the circuit is simple, I'm guessing it is. KC might know? Sounds like I should just use the 25v part.
You didn't mention voltage on the Wima, but assume 100v (smallest I see) will be fine. There is plenty of room on these boards for a .22uF bypass cap. I assume you are suggesting using the bypass cap in parallel with C1?
MKP1D032204D00KI00 WIMA | Mouser
I use Vishay-Roderstein 1837 MKP film caps (0.1uF, 160vdc) on my speaker crossovers with Mundorf Ecaps: MKP1D032204D00KI00 WIMA | Mouser
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If I look for MKP style film caps on Mouser with 4.7uF ... WIMA and Nichicon have one.
WIMA MKP4F044706F00KYSD WIMA | Mouser
Nichicon QAK2E475KTP Nichicon | Mouser
WIMA MKP4F044706F00KYSD WIMA | Mouser
Nichicon QAK2E475KTP Nichicon | Mouser
That’s decent thermal paste, have had good luck with that.
From what I know, the mkp10 is better than the other two choices. They use a construction where there are layers of film dielectric between the metalized layers, and the legalized layers have the metal on both sides. This helps keep the size down and still perform well vs many others I have tried for coupling applications.
A single 4.7uf 100v one should be fine, again, if you have the room, or can make it work with short leads, say 2” or so.
MKP1F044706J00JSSD WIMA | Capacitors | DigiKey
From what I know, the mkp10 is better than the other two choices. They use a construction where there are layers of film dielectric between the metalized layers, and the legalized layers have the metal on both sides. This helps keep the size down and still perform well vs many others I have tried for coupling applications.
A single 4.7uf 100v one should be fine, again, if you have the room, or can make it work with short leads, say 2” or so.
MKP1F044706J00JSSD WIMA | Capacitors | DigiKey
My order with be with Mouser, but they have that cap. If the legs are long enough, I can bend and fit into the pcb holes, which are 5mm apart.
MKP1F044706J00JSSD WIMA | Mouser
MKP1F044706J00JSSD WIMA | Mouser
Lower esr and more ripple rejection. The ones I am using are similar to the $58 Epcos b41570 I believe, and have .04 ohm esr, have been working with the original diode bridge now for several years
Also, if you can swing it, try and get a Wima FPK1, in both .01uf, and another MKP10 .1uf to make a snubber for the diode bridge. Those parts along with a 3 watt 18 ohm resistor will help to reduce the a/c noise as well as the noise from the diodes interacting with the transformer.
It just sounds smoother overall with added tonal qualities by not having the extra high frequency noise, if you’re interested in a fairly simple addition that is, if not, well it worked until now without it!
The .01uf goes across the two A/C terminals, while the .1uf is connected to the resistor, and then that assembly goes to the same points. If that makes sense.
Also, if you can swing it, try and get a Wima FPK1, in both .01uf, and another MKP10 .1uf to make a snubber for the diode bridge. Those parts along with a 3 watt 18 ohm resistor will help to reduce the a/c noise as well as the noise from the diodes interacting with the transformer.
It just sounds smoother overall with added tonal qualities by not having the extra high frequency noise, if you’re interested in a fairly simple addition that is, if not, well it worked until now without it!
The .01uf goes across the two A/C terminals, while the .1uf is connected to the resistor, and then that assembly goes to the same points. If that makes sense.
Most amps use a bipolar in the feedback position (C2) bypassed with a small value film. If it were mine I would use a Nichicon Muse ES bipolar for C2 and a small MKP film of .1uF in parallel across the pins.
For C1 I would do the same thing, use a Muse ES 47uF with a small value MKP film bypassing it.
That's my .02
For C1 I would do the same thing, use a Muse ES 47uF with a small value MKP film bypassing it.
That's my .02
No, but mine all use rectified A/C power, and have benefited from that additional circuit.
The bypassed muse es works well, I agree, however, all mkp are not made of equal quality, and may be better without a bypass in some cases.
Some interesting ideas here ... and since I don't know enough to choose, but here's my thoughts.
C1 - is a bipolar ... I can do the Nichicon Muse ES 47uf, with a Vishay-Roderstein 1837 MKP .1uf film cap. I posted that I've done that before on speaker crossovers with good results.
C2 - is not a bipolar cap ... are you saying that it can be?? I don't understand, but am trusting your advice. It is a 100uf, and I have space to make 220uF, if there is a benefit. The cost difference here is not a factor. If specific parts/values will improve sound, I want to do while in here. I'll have to look up what UES is ... Nichicon Muse ES bipolar?
In short, I'll use the small value MKP film on C1 and C2, so just need to select the cap type I want. If it's better to put a bipolar on C2, where it is not now, I'm okay with doing that. If I understand correctly, the use of a film bypass is to remove AC out of signal, and with a bipolar cap, you need that. Is that anywhere close to why I would do this?
C1 - is a bipolar ... I can do the Nichicon Muse ES 47uf, with a Vishay-Roderstein 1837 MKP .1uf film cap. I posted that I've done that before on speaker crossovers with good results.
C2 - is not a bipolar cap ... are you saying that it can be?? I don't understand, but am trusting your advice. It is a 100uf, and I have space to make 220uF, if there is a benefit. The cost difference here is not a factor. If specific parts/values will improve sound, I want to do while in here. I'll have to look up what UES is ... Nichicon Muse ES bipolar?
In short, I'll use the small value MKP film on C1 and C2, so just need to select the cap type I want. If it's better to put a bipolar on C2, where it is not now, I'm okay with doing that. If I understand correctly, the use of a film bypass is to remove AC out of signal, and with a bipolar cap, you need that. Is that anywhere close to why I would do this?
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