Buying filtering cap.

[Alan0354]

I think I am leaning towards F T cap for 22uF 500V as price is good.....Go German. For the reservoir, I am looking at MIEC 100uF 600V Dissipation Factor(DF=loss tangent) < 0.2 @120Hz.
Qty 2 100uF 600V 105C Axial Electrolytic Capacitors | eBay

I calculate: Equivalent Series Resistance ESR= DF X |Xc|=0.2 X [1/(2\pi f C)]=0.2X[1/(6.28X120X0.0001)]=0.2X13.3 ohm= 2.65 ohm. That is very low!!!!

For a 600V cap, I don't need to stack it up like the traditional Fender amps. So I have 100uF instead of two 70uF in series which is 35uF. On top, the ESR got to be lower than two of the ESR of the best cap in series. What do you guys think?

[nickb]

For a 600V cap, I don't need to stack it up like the traditional Fender amps. So I have 100uF instead of two 70uF in series which is 35uF. On top, the ESR got to be lower than two of the ESR of the best cap in series. What do you guys think?

Since you are concerned about aural effects, you might want to consider that whilst the ripple will be lower with the 100uF, the tube rectifier compression response will be different due to the altered time constant.

[Alan0354]

Since you are concerned about aural effects, you might want to consider that whilst the ripple will be lower with the 100uF, the tube rectifier compression response will be different due to the altered time constant.

Do you expect to have ripple ( 60, 120Hz etc.)? I looked at the Fender, I don't see any ripple. I had the scope on AC and at 2V/div and didn't see any. I see sag ( droop) when hitting the guitar hard, but not ripple I can remember. I thought droop ( sag) is the same regardless of the cap as the time constant is so long compare to the guitar signal.

But yet again, I don't have the ton of experience as you guys on tube amps. I kind of reading hear and read up more before buying. Might as well learn while spending money!!!

[Tom Phillips]

Do you expect to have ripple ( 60, 120Hz etc.)? I looked at the Fender, I don't see any ripple...

At the first filter cap I would expect to see 2% to 3% ripple at idle increasing as you crank up the output power. That's pretty typical for a Pro Reverb.

[nickb]

Do you expect to have ripple ( 60, 120Hz etc.)? I looked at the Fender, I don't see any ripple. I had the scope on AC and at 2V/div and didn't see any. I see sag ( droop) when hitting the guitar hard, but not ripple I can remember. I thought droop ( sag) is the same regardless of the cap as the time constant is so long compare to the guitar signal.

But yet again, I don't have the ton of experience as you guys on tube amps. I kind of reading hear and read up more before buying. Might as well learn while spending money!!!

You should see a few volts of ripple. The greater the load the greater the ripple. The time constant is significant in my view, although I'll leave the subjective assessment of audibility to others. Here is a comparison of expected sag for 35uF (green) and 100uF (blue) with ripple removed for clarity.

[Alan0354]

Anyone has experience with how the amp sounds with different values reservoir cap and screen cap?

[Alan0354]

Looking further, try Tube depot, I see both F&T and IC both selling for the same $3.95, your choice.

https://tubedepot.com/t/diy-central/...s/electrolytic

Ordered 6 of the 22uF 500V, 2 of the 100uF 450V, 2 of the 100uF 100V from them. I also bought a bias probe for $19. That's cheap. Their shipment is particular cheap. The whole order is $3.05!!! On ebay, the shipment can eat you alive!!!

Thanks for you information, that really help.

[big_teee]

Has anyone tried any of these 600v Caps?
I thought about buying a few of them, and it would cut down on the need for Series, and cut down on real estate required in most amps running + or - 500v HT.
100UF 600V 105C Axial Electrolytic Capacitor

[Alan0354]

Has anyone tried any of these 600v Caps?
I thought about buying a few of them, and it would cut down on the need for Series, and cut down on real estate required in most amps running + or - 500v HT.
100UF 600V 105C Axial Electrolytic Capacitor

I almost going to try it. It's the MIEC cap that Nickb suggested. I was going to get the 100uF 600V for the reservoir cap, but they are not cheap and also Tube Depot has the F T cap really cheap and shipment is cheap. It's a money decision I went with all F T caps.

Their ESR spec is very low too, only 0.2 for the 100uF.

[big_teee]

I almost going to try it. It's the MIEC cap that Nickb suggested. I was going to get the 100uF 600V for the reservoir cap, but they are not cheap and also Tube Depot has the F T cap really cheap and shipment is cheap. It's a money decision I went with all F T caps.

Their ESR spec is very low too, only 0.2 for the 100uF.

But if your dealing with 500v or more then the Caps have to be used in Series.
Then you need 2 200uf Caps, or 4 100uf caps parallel series to get the same 100uf you get with 1 600v 100uf cap.
So that seems to make the price of 1 100uf 600v much more affordable, plus it takes a lot more real estate once you start doing the series thing.
If you're safely under the 500v, then there is no need for series or the 600v Caps.
$10 for 100uf 600v looks like a pretty good deal to me.
Just wondered if anyone had used them?
I still have a medium high V bass amp in mind.
T

[Alan0354]

But if your dealing with 500v or more then the Caps have to be used in Series.
Then you need 2 200uf Caps, or 4 100uf caps parallel series to get the same 100uf you get with 1 600v 100uf cap.
So that seems to make the price of 1 100uf 600v much more affordable, plus it takes a lot more real estate once you start doing the series thing.
If you're safely under the 500v, then there is no need for series or the 600v Caps.
$10 for 100uf 600v looks like a pretty good deal to me.
Just wondered if anyone had used them?
I still have a medium high V bass amp in mind.
T

Yes, but the 22uF is cheap and made in German. Shipping is cheap when combined. There is some argument on changing the size of the cap change the sound. I don't know whether I can agree with that. But I really want this amp to sound original, so the original caps are 70uF in series, two of the 100uF is closer, that would be 50uF.

I know, I was really tempted by the MIEC caps.

[big_teee]

Yes, but the 22uF is cheap and made in German. Shipping is cheap when combined. There is some argument on changing the size of the cap change the sound. I don't know whether I can agree with that. But I really want this amp to sound original, so the original caps are 70uF in series, two of the 100uF is closer, that would be 50uF.

I know, I was really tempted by the MIEC caps.

Agreed, good luck.
I used the FTs in a marshall build, they worked good, I used the JJs in the Second build, they were fine also.
Just wondered if anyone had tried the 600v 105c Studio Electronics Caps for other Applications.
They don't have a brand on them, but for $10 each, not a bad deal.
T