Bottlehead Forum

Bottlehead Kits => S.E.X. Kit => Topic started by: audiblesoundwave on December 11, 2009, 07:58:13 AM

Title: 22uf 450v cap upgrade! Is it a good thing?
Post by: audiblesoundwave on December 11, 2009, 07:58:13 AM
Hi,

Is there any sonic benefits/improvement from upgrading the 22uf 450v cap? 

I am thinking about using the Obbligato Film Oil Caps 22uf 630v as I have for the 47uf 450v to Obbligato Film Oil Caps 70uf 630v!

I searched the forums (current and the old) and did not really find anything close to this upgrade. 

Any sharing, comments?

Thanks,
Milton
Title: Re: 22uf 450v cap upgrade! Is it a good thing?
Post by: Grainger49 on December 11, 2009, 10:29:54 AM
Most likely.  I think the 47uF@450 would benefit from an upgrade too.  

The 22uF is closest to the driver tube plate, the 47uF is closest to the output plate.  I'm thinking that the output is more important.  Like upgrading audio path caps, the output cap is more important, more bang for the buck, than the interstage.  Both make an improvement.

If you are going to place an order why not get caps for both?
Title: Re: 22uf 450v cap upgrade! Is it a good thing?
Post by: Jim R. on December 11, 2009, 10:38:45 AM
How big are those guys -- 22 and 47?
Title: Re: 22uf 450v cap upgrade! Is it a good thing?
Post by: Grainger49 on December 11, 2009, 11:16:57 AM
The 22uF and 47uF are sizable.  The 220uF@200V first stage filter/voltage doubler caps are the familiar Pi network caps from the Foreplay and Seduction.  

If you were asking about the size of the Obbligato caps, they are BIG!  If they were not insulated with wire leads they wouldn't fit on/under the hood of the SEX.  In fact I don't know for certain.  Someone else should speak up for that.  The sizes should be available from DIY Hi-Fi Supply.

The 22uF and 30uF 630 PP Film/Oil are 115mmX45mm and 115mmX52mm.  The 70uF is 125mmX54mm.

Like I said, BIG!
Title: Re: 22uf 450v cap upgrade! Is it a good thing?
Post by: tsingle999 on December 11, 2009, 11:24:35 AM
I put a 47uf black gate and i liked the difference. I replaced the 22uf with a humongous obbligato. I am not sure I liked the change musically. Physically it required some delicate strapping to keep the cap secure and the base had to be raised on brass footers so there was enough room for it. It will not fit with the standard feet. Replace both the 22 and 47 with obbligato's and you will have some serious issues - may need a new base. I willpost a photo later...
Title: Re: 22uf 450v cap upgrade! Is it a good thing?
Post by: audiblesoundwave on December 11, 2009, 11:45:06 AM
Hi Tsingle999,

What you don't like about from the 22uf Obbligato upgrade?  Can you please give a bit more detail on the sonic change?

Thanks,
Milton
Title: Re: 22uf 450v cap upgrade! Is it a good thing?
Post by: tsingle999 on December 12, 2009, 03:33:52 AM
I don't think it was a huge difference but its hard for me to describe but it didn't seem to have the life or sparkle it did before??? It's a hard thing for me to describe.....But for the cost i would try it and see for yourself. I put in an expensive DACT volume control and I didn't like that change very much either. The thing is for the most part theses things change the sound and you may like it or you may not. But you never know until you try....
Title: Re: 22uf 450v cap upgrade! Is it a good thing?
Post by: BNAL on December 12, 2009, 02:54:23 PM
How mush time do you have on the caps? That maybe the reason they do not sound good. I have found that it takes time for caps to sound their best.
Title: Re: 22uf 450v cap upgrade! Is it a good thing?
Post by: Paul Joppa on December 12, 2009, 04:15:00 PM
Here's an interesting question - how long does it take for a cap to break in if it carries almost no AC current?

A normal power supply capacitor in a series feed amp carries the full output signal current. But the 22uF in a SEX amp, especially one with the C4S for a plate load on the driver, has hardly any AC current - mostly just the traces of ripple that remain after the main filter and no signal to speak of at all. It's already hard to hear the cap, isolated by the C4S (not impossible as several listeners have attested!) - does it also take an extra long time to break in?
Title: Re: 22uf 450v cap upgrade! Is it a good thing?
Post by: tsingle999 on December 14, 2009, 08:00:12 AM
Great question! I have had mine in for 2 years with a lot of hours on it (at least 1000) So long its impossible for me to remember what the amp used to sound like! lol. I do like the amp a lot right now with those caps in but maybe i should A/B them to see the difference now.