Capacitor test

[Bob-I]

There's so much debate of cap types that decided to use my latest build as a test.

I have a bunch of xicon blue polyester caps that I bought years ago so I built the amp using these wherever I had the value. Except for OD1 and OD2 coupling caps and the mid TS cap, which are orange drop PS, every TS and coupling cap was a polyester.

The result was good, the overall sound of the amp is what I expected. No big suprises.

Last night I tried 2 substitutions.

1) I put in orange drop 715's. Basically there was no change in tone. I thought that I heard a little more brightness but not much of a change. This can be chalked up to tolerance. Overall the amp still sounded great.

2) I subbed in xicon MPP, metalized polypropelyne. Immediatly I heard a big improvement. The mids are more complex, and highs smoother. Some of the high end harshness I was hearing is gone. The lows don't seem to be changed, mostly it's the mids and highs.

I don't have enough of the PS series orange drops so I can't test them in all positions but I put them in the TS and I didn't hear a difference between the MPP and PS.

My conclusion is that the xicon MPP are right for these amps on all TS and coupling caps, except the treble cap of course which should be a ceramic.

That's my story and I'm sticking to it.


P.S. make sure that you get at least 400V MPP's. The 250V's are too low. I got the 630V.

[Normster]

I've still got a whole bag of PS caps, but sooner or later I want to try the MPPs. Something about a smaller, cheaper, great sounding cap that appeals to me.

[dogears]

Did you try comparing the MPP to PS in the critical coupling positions?? I'd be interested in your feedback.

[Bob-I]

Did you try comparing the MPP to PS in the critical coupling positions?? I'd be interested in your feedback.

No, only in the TS, no noticable difference there.

[dogears]

I wouldn't expect a difference there as the caps are to ground. The CL2, OD1, OD2, PI, and Outputs are what would matter IMO.

Try the CL2 and OD1-2 change and report back..... If you'd be so kind...

Did you try comparing the MPP to PS in the critical coupling positions?? I'd be interested in your feedback.

No, only in the TS, no noticable difference there.

[Bob-I]

I wouldn't expect a difference there as the caps are to ground. The CL2, OD1, OD2, PI, and Outputs are what would matter IMO.

Try the CL2 and OD1-2 change and report back..... If you'd be so kind...

I'd like to compare too, but I don't have PS in the right values.

[Bob-I]

I wouldn't expect a difference there as the caps are to ground. The CL2, OD1, OD2, PI, and Outputs are what would matter IMO.

I don't know that I agree there. The TS Caps act as the coupling caps between CL1 and CL2. Only part of the signal goes to ground, the rest passes through the TS caps.

[dogears]

To a small degree I suppose The treb cap being most important IMHO

I wouldn't expect a difference there as the caps are to ground. The CL2, OD1, OD2, PI, and Outputs are what would matter IMO.

I don't know that I agree there. The TS Caps act as the coupling caps between CL1 and CL2. Only part of the signal goes to ground, the rest passes through the TS caps.

[Bob-I]

To a small degree I suppose The treb cap being most important IMHO

Maybe, but I heard a big difference when I swapped the mid and bass caps from 715's to MPP's. I'd say it was as much as the PI and power tube coupling caps.

BTW, I also noticed that the MPP's are brighter than the same value 715's. I upped the OD1 coupler from .01 to .022, and OD2 from .0047 715 to .0056 PS.

But you're entitled to your opinion, no matter how wrong it may be

[dogears]

Bob,

Try going back to .01 on OD1. Then raise the Cl2 bypass to 10uf instead. Much better to my dogears..... 1uf doesn't do it at all for me.

To a small degree I suppose The treb cap being most important IMHO

Maybe, but I heard a big difference when I swapped the mid and bass caps from 715's to MPP's. I'd say it was as much as the PI and power tube coupling caps.

BTW, I also noticed that the MPP's are brighter than the same value 715's. I upped the OD1 coupler from .01 to .022, and OD2 from .0047 715 to .0056 PS.

But you're entitled to your opinion, no matter how wrong it may be

[Bob-I]

Bob,

Try going back to .01 on OD1. Then raise the Cl2 bypass to 10uf instead. Much better to my dogears..... 1uf doesn't do it at all for me.

I have a 5uF on CL2 bypass now. I'll have to play a bit with these values.

[Bob-I]

Bob,

Try going back to .01 on OD1. Then raise the Cl2 bypass to 10uf instead. Much better to my dogears..... 1uf doesn't do it at all for me.

I have a 5uF on CL2 bypass now. I'll have to play a bit with these values.

Once again I bow to the master... the 10uF really fattened up the OD and the .01uF adds the shimmer.

[dogears]

Bob,

Try going back to .01 on OD1. Then raise the Cl2 bypass to 10uf instead. Much better to my dogears..... 1uf doesn't do it at all for me.

I have a 5uF on CL2 bypass now. I'll have to play a bit with these values.

Once again I bow to the master... the 10uF really fattened up the OD and the .01uF adds the shimmer.

[Darkbluemurder]

There's so much debate of cap types that decided to use my latest build as a test.

I have a bunch of xicon blue polyester caps that I bought years ago so I built the amp using these wherever I had the value. Except for OD1 and OD2 coupling caps and the mid TS cap, which are orange drop PS, every TS and coupling cap was a polyester.

The result was good, the overall sound of the amp is what I expected. No big suprises.

Last night I tried 2 substitutions.

1) I put in orange drop 715's. Basically there was no change in tone. I thought that I heard a little more brightness but not much of a change. This can be chalked up to tolerance. Overall the amp still sounded great.

2) I subbed in xicon MPP, metalized polypropelyne. Immediatly I heard a big improvement. The mids are more complex, and highs smoother. Some of the high end harshness I was hearing is gone. The lows don't seem to be changed, mostly it's the mids and highs.

I don't have enough of the PS series orange drops so I can't test them in all positions but I put them in the TS and I didn't hear a difference between the MPP and PS.

My conclusion is that the xicon MPP are right for these amps on all TS and coupling caps, except the treble cap of course which should be a ceramic.

That's my story and I'm sticking to it.


P.S. make sure that you get at least 400V MPP's. The 250V's are too low. I got the 630V.

That is very interesting. I use 715 ODs as standard. However in one amp I used Xicons (I don't know which model they are but they are quite small and have a dark red colour) as the PI coupling caps simply because they were the only 0.1uF I had left. They sound good. How do the Xicon MPP caps look like? I purchased mine from Antique Electronic Supply.

Has anyone tried Sozos in their D-style amp?
And BTW what does PS mean (polystyrene)?

Cheers
Stephan

[Bob-I]

That is very interesting. I use 715 ODs as standard. However in one amp I used Xicons (I don't know which model they are but they are quite small and have a dark red colour) as the PI coupling caps simply because they were the only 0.1uF I had left. They sound good. How do the Xicon MPP caps look like? I purchased mine from Antique Electronic Supply.

Yes, AES sells the xicon MPP caps.

Has anyone tried Sozos in their D-style amp?
And BTW what does PS mean (polystyrene)?

Cheers
Stephan

The PS Series are Polyester film. I have no idea how they arrived at PS from that.

I too have used 715's as the standard, but I've reached a point where I need to get to the next level of tone. The caps seem to have a subtle but noticable effect on the tone. I also like the MPP's because of the size, especally since I'm building in a Princeton chassis.