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Post subject: Re capping Hot Rod Deville
Posted: Sat Nov 01, 2014 4:29 pm
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I just bought my first decent amp, HRD, and I'm a happy chap. It's seen a lot of use and I've ordered some new tubes, but I also want to change out the old electrolytic caps.

I've seen the Fromel kit, and it seems comprehensive, but the cost by the time it arrives in the UK is quite high for a handful of caps and bits.

Is there a link to a "how to do" thread for this job, one with a bill of materials for caps that need doing most, and where to spend money on silver mica perhaps?

I'm no tech, but I can solder well enough and favor the paint numbers approach if the instructions are available.

Many thanks for your time.


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Post subject: Re: Re capping Hot Rod Deville
Posted: Sun Nov 02, 2014 1:50 am
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A "new" amp like HRD may not need new filter caps if you don't you hear some hum or ... ?
These filter caps can't not be old .

It is a amp not easy to work not to say more . Take lots of time and skill and some knowledge too.

You can do more problem if you work on and you are not qualified .Some wire must stay in same place and if you move them you may have a some noise. These wires are " bend " to do less noise .

Printed circuit boar ( copper ) is fragile .

As we say if it work well don't fix it .

Don't do that .


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Post subject: Re: Re capping Hot Rod Deville
Posted: Sun Nov 02, 2014 9:30 am
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It's not a new amp as such, a tweed version with no information inside to date it. From what I know of it, it's no spring chicken.

There is plenty of crackle and pop when I fire her up, this fades away after she's warm.

Sound quality should be better, I'm using a Godin LGX with Seymor Duncan CC and Jazz. The clean chanel is very hard to make clean and there is a complete lack of warmth or musical fuzz as the signal gets driven.

I've bought 2 tesla 6l6GC JJ Cryo, and 3 12ax7 electro harmonic. Expecting improvements there, fingers crossed.

Next is the caps, regardless of "hum" which can come from many different problems, poor caps in the signal path are especially detrimental. So the Fromel approach looks appealing.

I may also take the amp out and build it its own header, covered in tweed tolex of course.


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Post subject: Re: Re capping Hot Rod Deville
Posted: Sun Nov 02, 2014 9:53 am
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Lorienblack wrote:
It's not a new amp as such, a tweed version with no information inside to date it. From what I know of it, it's no spring chicken.

Caps are dry when more than 30 and 40 years old , to me a HRD is a modern amp = new

There is plenty of crackle and pop when I fire her up, this fades away after she's warm.
Broken solders or broken copper printed circuit , rusty or loose tubes contacts , bad tubes

Sound quality should be better, I'm using a Godin LGX with Seymor Duncan CC and Jazz. The clean chanel is very hard to make clean and there is a complete lack of warmth or musical fuzz as the signal gets driven.
Phase inverter circuit / tube.

I've bought 2 tesla 6l6GC JJ Cryo, and 3 12ax7 electro harmonic. Expecting improvements there, fingers crossed.
Need to check bias

Next is the caps, regardless of "hum" which can come from many different problems, poor caps in the signal path are especially detrimental. So the Fromel approach looks appealing.

I may also take the amp out and build it its own header, covered in tweed tolex of course.


With what you say , filter caps are good. Better to see a qualified tech .

What is the "Fromel Approach " ?


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Post subject: Re: Re capping Hot Rod Deville
Posted: Sun Nov 02, 2014 11:41 am
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Don't forget the bad cap era. I know some blues jr's suffered from this. But if the caps are showing no signs of failure (physically inspect them to see if they are leaking) then they are good and will remain so for many many years.

Fromel makes kits for fender amps. Kind of like BillMaudio's kits.

Having put a BillM kit (not a re-cap kit tho I did buy it) into my blues jr I would not change out the caps unless I thought they were bad. I think those boards are more fragile than you'd want.


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Post subject: Re: Re capping Hot Rod Deville
Posted: Sun Nov 02, 2014 11:43 am
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DarkPenguin wrote:
D

Having put a BillM kit (not a re-cap kit tho I did buy it) into my blues jr I would not change out the caps unless I thought they were bad. I think those boards are more fragile than you'd want.



+1000


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Post subject: Re: Re capping Hot Rod Deville
Posted: Mon Nov 03, 2014 9:49 am
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Hmm good point about the fragile boards, and thanks for the tips re the issues I have found with the amp so far.

I have some Elecroharmonic 12AX7's and some JJ cryo 6l6 arriving in the post tomorrow so I may be grinning from ear to ear soon :)

I do however think replacing old mediocre caps in the signal path, with some silver mica would be worth the risk. I build my own hi-fi, amps/Dac's/speakers and swapping out caps can yield remarkable improvements.

Thanks for the help guys


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Post subject: Re: Re capping Hot Rod Deville
Posted: Mon Nov 03, 2014 11:00 am
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Come back to tell us how it soud good after your mod .

Take lots of picture before removing printed circuit , it could be usefull later .... :D


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