Questions On Ampeg V4 Filter Caps For The Experienced Techs

[RickyLee]

I have been looking around on the web for replacement filter caps for my early 70's Ampeg V4. The web keeps leading me to the Fliptops web page. They offer a quite pricey recap kit for $105 that has the close cap values and they are the insulated twist lock style can cap as well. But I can't find info on the manufacturer of these 70 40 40 can caps. They also offer another version of the kit using F & T caps which I would prefer to use as well as it is only $89. But I am assuming these are not the same style as my originals with the twist lock as well as the outer insulated. What makes this amp circuit a bit different is the series/parallel config. and values of the filtering. I do not need to go into this for you seasoned guys that already know what I am talking about here.

Anyone have experience with these generic looking can caps from Fliptops?

Fliptops


Here's the kit using F & T's

Fliptops



Then they have this can cap individually that is actually the correct multi X 3 for what my amp has, but it is not in the kit?? And freakin' pricey as well as no known name brand manufacture??

http://www.fliptops.net/catalog/product_info.php?cPath=25_54&products_id=801


Some questions for you experienced techs who have possibly worked on a few of these old Ampegs?

 

[TwinACStacks]

Ricky you can use other values with a rather complicated rewire. I used the set from Fliptops in my old V4 Check THIS forum and see if there are some tech articles:

Ampeg V4.com | All Ampeg All The Time

These V4's are some of the best amps ever made. Heavy bastards though.

TWIN

 

[RickyLee]

Thanks Twin. Thanks Twin.

Yeah, I am contemplating using my own different array of caps and values to get what it needs. But then there's not much room inside to do a relocate mod. That's what I was wondering if any of the tech pros here might have done?

Yeah, that Ampeg forum is awesome. I have already been on there quite a bit.

And these V4's are freakin' heavy tanks for sure! Which version did you go with on those Fliptop kits?

 

[TwinACStacks]

Ricky Mine, was a '76 without the distortion I had to go with the $105.00 kit.

You ought to lift an SVT sometime...

TWIN

 

[TradAmpGuy]

Yeah, V4s are back breakers. Great amp though. Mine needs caps bad as well. Still debating which kit I want.

 

[MM54]

Ricky you can use other values with a rather complicated rewire. I used the set from Fliptops in my old V4 Check THIS forum and see if there are some tech articles:

Ampeg V4.com | All Ampeg All The Time

These V4's are some of the best amps ever made. Heavy bastards though.

TWIN

I played roadie one night as a favor for a friend of a friend who has a V4. Fucking hell they weigh a ton, it was heavier than his cab (Seemed really big, too)

 

[Neal]

RickyLee, I recap many V4/VT22/V2's and I use caps from Weber. I use 2 - 100uf/100uf-500V can caps for the duplex section, but 50uf/50uf-500V cans are ok, then I use a 20uf/600V cap which eliminates the need for for the "shared" half-can/half-discrete electrolytic cap, a 50uf/50uf-500V can cap and a 50uf/450V electrolytic for the 3rd cap can. Weber doesn't have the 100K-2W resistors for the can caps. I had those on hand. All the can caps come with the clamps and all the Weber stuff cost less than $32+S&H. You can get the resistors at Antique Electronics for $2 for a bag of 5 +S&H.

 

[Riv]

I know this is an older thread but can someone tell me what's the difference between the 2 fliptop kits, and how will they affect the amp?
Thanks.

 

[RickyLee]

I know this is an older thread but can someone tell me what's the difference between the 2 fliptop kits, and how will they affect the amp?
Thanks.

Welcome!

Can you post links to the kits you are looking at? I am remembering there was three kits for that? Or am I wrong on that?

I just pieced together my own caps on that and did not buy those cap kits. But obviously, if you are going to try and keep the original look, you will want one of those kits.

What did you mean by "affect the amp"? Are you talking cosmetics? Or the actual cap values and filtering?

 

[Riv]

Well,
I guess I'll start with what my problem is.
I recently got a V4 but I noticed that the sound level would drop (I'm also getting popping when I switch fx).
I replaced the power tubes and the same thing is still happening so I ordered all the tubes needed to replace everything.
I might be getting ahead of myself but I'm guessing if I still have any of these problems that I should change the caps and was looking into the fliptop kits.

 

[RickyLee]

It is a good idea to change out all electrolytic caps throughout if they are the originals due to the age of those caps. Give all the tube/valve sockets a good cleaning as well.

I ended up changing most of the coupling caps out on mine and I put 5W 10 ohm wire wound resistors on all the power valve plates. This also simplifies checking the bias as well. And I also swapped out the screen grid resistors to 5W 1K.

Be very careful working inside, as these amps run well over 500VDC. My B+ on my Ampeg V4 is aprox. 540VDC. Mine is a '72.

Which power valves did you go with?

 

[Riv]

Sovtek 7027A

The rest of what you're saying to me is another language.
I want to learn my amp and would like to be able to do these things myself but I might be getting over my head on this one.
The only experience I have is changing pick ups and pots on my Bass.

 

[alanthecowboy]

Hey All... just joined, and thought I'd throw my $0.02 in, as I just finished a rebuild on a V4B (sorry, a bass player is crashing the party...)

The cheaper F+T kit comes with values that are close to the original, especially a 25V/800V screen cap. The screen supply runs at over 500V on these, so the 40uF/500V cap that comes with the more expensive kit is not going to be happy for very long.

That said, the more expensive kit comes with 40% more capacitance on the B+ supply, which is a good thing for these units. The stock caps in my amp were a pair of 40/70 in series, which works out to 55uF. In my opinion, every stage of filtering in the V4 needs to be increased, so I don't think either of the kits are ideal. Next time, I'm going to check out the Weber caps Neal was referring to, as the values he found are ideal; thanks for that!

Anyway, the important thing is that neither of these kits seem to include bias supply caps, and if you recap one of these without changing the bias caps, you're going to be going back in again...

Mine uses a pair of 10uF/100V caps; if they are leaky they change the resistance on the ground side of the voltage divider, causing the bias voltage to drift down, which is not the direction you want it to drift... I finished my first power up test with my new JJ6L6's running at just under 200% of rated power, instead of my intended 70%, and realized I'd better change those bias caps... Luckily I didn't break anything.

Really, that's all I wanted to say; don't spend the money on a recap/retube and then risk it all for the sake of a couple of fifty cent parts... BTW, might as well change the 0.047 bias feed cap while you're in there.

Cheers!

 

[RickyLee]

Hey All... just joined, and thought I'd throw my $0.02 in, as I just finished a rebuild on a V4B (sorry, a bass player is crashing the party...)

The cheaper F+T kit comes with values that are close to the original, especially a 25V/800V screen cap. The screen supply runs at over 500V on these, so the 40uF/500V cap that comes with the more expensive kit is not going to be happy for very long.

That said, the more expensive kit comes with 40% more capacitance on the B+ supply, which is a good thing for these units. The stock caps in my amp were a pair of 40/70 in series, which works out to 55uF. In my opinion, every stage of filtering in the V4 needs to be increased, so I don't think either of the kits are ideal. Next time, I'm going to check out the Weber caps Neal was referring to, as the values he found are ideal; thanks for that!

Anyway, the important thing is that neither of these kits seem to include bias supply caps, and if you recap one of these without changing the bias caps, you're going to be going back in again...

Mine uses a pair of 10uF/100V caps; if they are leaky they change the resistance on the ground side of the voltage divider, causing the bias voltage to drift down, which is not the direction you want it to drift... I finished my first power up test with my new JJ6L6's running at just under 200% of rated power, instead of my intended 70%, and realized I'd better change those bias caps... Luckily I didn't break anything.

Really, that's all I wanted to say; don't spend the money on a recap/retube and then risk it all for the sake of a couple of fifty cent parts... BTW, might as well change the 0.047 bias feed cap while you're in there.

Cheers!

Good Info! And a Welcome to you as well.

I actually increased the ratings and capacitance value on all sections of the B+ rail by putting my own configuration of caps together. The majority of my caps were F&T which I prefer anyway. It was not as simple as the kit array, but it was not that hard either. You just need to wrap your brain around it with a pencil and paper for a few minutes. My amps sounds so much better with the increased filtering.

I can't tell you off the top of my head what I did. I will see if I can find my notes if I get a chance.

I would pull the amp out and look inside for you, but unfortunately for me that is not physically possible at this time as I am having some major health issues with my lower back and right leg.




EDIT: Actually, I think there is a thread here on exactly what I did if you want to search it out. I always have a tough time with this search function myself - I will se what I can find.

 

[RickyLee]

I don't know if you are interested in this info on how I did my Ampeg re-cap? But it does require a bit more work than the Fliptop kits. But my re-cap gives you a bit more filtering in all the stages and is a bit cheaper as well. But then again, some people prefer less filtering anyway. And if you are wanting to keep the original look to your amp, then the Fliptop kits would be the way to go. My method requires two of those Ampeg FP cans to be converted to the clamp style you would see in a JCM800 for example using two F&T multi sections. And the third FP type CE brand 40 40 40 can would use a new wafer and mount like the originals.

Then there is a fourth smaller cap that goes inside the chassis and is held in place by a small clamp similar to a hose clamp. Bummer here regarding that clamp, is that is has a rivet and can't be adjusted for the diameter sizing. I am remembering that I had to come up with a new clamp or used zip ties or something to make my new cap sit inside. That is the one I am calling the "F & T 100uF 450V axial".

Just depends how adventurous you are and what you want done.

Here is my old info I found. But I ended up going through Antique Electronic Supply as they had that CE brand triple section 40/40/40uF 525V:

I will try the 67uF plate, 50uF screen (two F & T 100uF 100uF 500V, and one F & T 100uF 450V axial) and then the CE USA 40uF 40uF 40uF 525V (replaces the triple 40uF). That multi can CE is the expensive one at $36.95 YIKES! I think I am going to order my caps tonight through tubedepot.com, and it will cost me aprox. $84 before shipping and give me more filtering as well. The Fliptops kit I was looking at was $109. But then those Fliptop kits did come with the brackets and such.