Refreshing Older Hafler Amp...

Systems

The voltage must atleast be the same but can be higher.You can use larger values of capacitance and will be benificial for the filter caps.But if it is increased too much you may have problems with fuses blowing at turn on do to increased current demand as the caps try to fully charge at turn on.You could just use a higher value fuse or better yet a soft start circuit.The 27000uf should be fine but are they insanely priced?I would get the ones you linked to at Mouser they should be easy to install as they are the can type like the originals and rationally priced.

jakelm

GV, I will copy my other post here from the amp thread.

Thank you GV. Your saying you have the tab mount type? If you think that would work and if you have the right size, I'll take you up on that offer. I will replace both c1's as you recommended.

C5 is electrolytic, C6 is Mica.

jakelm

Thanks for all the help guys....

Jake



P.S See how easy and fun it is when you have friends who know what they are doing..

jakelm

Do you think the Mica caps need replacing.

I am not familliar with Mica caps.

Really the only caps I am familiar with are crossover caps (Maylar, electrolytic, Solen, etc.)

jakelm

I found a pic of one...seen these before

jakelm

School just called I start in January...wooohoo!! Finances are set..


Funny how things happen. I was sitting here talking to a electronics technician, who is here doing some work for the boss, about the project I was doing on my amp. The guy had no idea what I was talking about. He is a certified electronics techincian!! He said...we just change parts..not much bench work..

The conversation started about me asking him if he knew what a Mica cap was, he had no idea. Then the phone rang, it was the finacial aid girl from college saying everything was aproved.

Funny how things happen.

Jake

jakelm

Ok this is what I'm ordering from mouser.

I wanted to go over the order before I comit to it.

C1 replacing with:

Nichicon Bi-Polar Aluminum Electrolytic Capacitors
16V 10uF 5X11 - RoHS: COMPLIANT

C5 replacing with:

Nichicon Bi-Polar Aluminum Electrolytic Capacitors
6.3V 470uF 10X12.5 - RoHS: COMPLIANT

The questions I have. For the larger PS can capacitors, would you recomend larger than what is in there right now, or go with the same size? Would larger be helpfull?

Also, the Mica caps, should they be changed as well or do they hold up pretty well?

C7 and C10, the excact size is not avaliable with mouser, what size should I get?

I was told that film caps should still be good sinc they dont break down as quickly.

jakelm

C7 and C10 are 100uF 80V caps. The closest mouser has is 100uF 100v. Would this be ok?

heiney9

jakelm wrote: »

Ok this is what I'm ordering from mouser.

I wanted to go over the order before I comit to it.

C1 replacing with:

Nichicon Bi-Polar Aluminum Electrolytic Capacitors
16V 10uF 5X11 - RoHS: COMPLIANT

C5 replacing with:

Nichicon Bi-Polar Aluminum Electrolytic Capacitors
6.3V 470uF 10X12.5 - RoHS: COMPLIANT

The questions I have. For the larger PS can capacitors, would you recomend larger than what is in there right now, or go with the same size? Would larger be helpfull?

Also, the Mica caps, should they be changed as well or do they hold up pretty well?

C7 and C10, the excact size is not avaliable with mouser, what size should I get?

I was told that film caps should still be good sinc they dont break down as quickly.

It's best to go with the same capacitance rating on the PS if at all possible. Higher voltage is alright to a point and even a bit more capacitance is alright but going way over the cap value is not a good thing overall.

Also if any of those electrolytics you have listed as replacements are in the signal path I'd reconsider using some other material makeup, unless they are odd ball size and value. Anything not in the signal path can be electrolytic if you want to save some $$$. This is just my .02c everyone has a bit different opinion.


H9

heiney9

jakelm wrote: »

C7 and C10 are 100uF 80V caps. The closest mouser has is 100uF 100v. Would this be ok?

Yes.

heiney9

I will also say new electrolytics are still better than the aged caps in the amplifier already. I'm a bit more anal so I would tend to replace the caps with non-electrolytic. But so far you are doing fine and will see some good improvement in the amp when you are done.

Keep a fire extinguisher handy .

H9

jakelm

Thanks H9.

The C1 caps are in the input signal path.

The C5 caps are in the loop feedback path.

The C6 is also in the loop path , but it a Mica cap. I dont see anything like that at mouser. Or at least anything saying Mica.

jakelm

heiney9 wrote: »

Keep a fire extinguisher handy .

H9

**** man...dont tell me that...lol:D :eek:

jakelm

When you speak of non-electrolytic, ceramic or film is prefered?

jakelm

I found the Mica

This should work for C6 loop

CDE Mica Radial Lead Capacitors
270pF 500V +/-5% - RoHS: COMPLIANT by Exemption

heiney9

jakelm wrote: »

**** man...dont tell me that...lol:D :eek:

It's Murphy's Law.....if you have one handy nothing will happen.....if you don't....well........

Seriously if you do things carefully one at a time and all the new parts are the same value or higher you won't have any issue's. But it's always better to be safe than sorry.

H9

jakelm

heiney9 wrote: »

It's Murphy's Law.....if you have one handy nothing will happen.....if you don't....well........

Seriously if you do things carefully one at a time and all the new parts are the same value or higher you won't have any issue's. But it's always better to be safe than sorry.

H9

True... I have one...I will put it at my side.

jakelm

I have to admit, this is alot more difficult than a simple crossover upgrade.


But when its done and my friends come over (the very few I have..lol) they will say how well it sounds, I can just sit back, grin and go..yep..I did that...:p

heiney9

jakelm wrote: »

I have to admit, this is alot more difficult than a simple crossover upgrade.

Yes it is and I for one have never tried it and I probably won't simply because I understand the "book" part of it but am terrible at applying that knowledge in an actual physical project. Speaker x-overs are my limit at this point. Plus I have very litle patience at times and with electronics, epsecially troubleshooting, you need lots and lots of patience. LoL

jakelm

But you save a ton of $$ doing it yourself.

hearingimpared

Cool and quite a coincidence. I've been kicking around the idea of resurecting an old Hafler DH-180 for my bedroom rig. I did Musical Concepts upgrades to it back in 1989. This thread is definitely helpful.

jakelm

No offence to musical concepts, but for the price they want to referb or add their new board, you could buy a nice used amp.

jakelm

If not electrolytic in the signal path, then which of these would you select?

jakelm

They dont have the size i need in a non-eletrolytic cap. I looked under polypropylene.

Systems

jakelm wrote: »

I wanted to go over the order before I comit to it.

C1 replacing with:

Nichicon Bi-Polar Aluminum Electrolytic Capacitors
16V 10uF 5X11 - RoHS: COMPLIANT

C5 replacing with:

Nichicon Bi-Polar Aluminum Electrolytic Capacitors
6.3V 470uF 10X12.5 - RoHS: COMPLIANT

The questions I have. For the larger PS can capacitors, would you recomend larger than what is in there right now, or go with the same size? Would larger be helpfull?

Also, the Mica caps, should they be changed as well or do they hold up pretty well?

C7 and C10, the excact size is not avaliable with mouser, what size should I get?

I was told that film caps should still be good sinc they dont break down as quickly.

For C 1 I would go with a film cap.The Panasonic ECQ-E line from Digi Key would be a good choice if you can fit them on the board and cost $5.78 ea.Digi key part #EF-1106-ND. They are 10uf 100volt polyesters.

The Micas should still be OK ,but I would replace C5.The Nichicon replacement you mention is fine.

For the filter caps you can use bigger values and it does have performance advantages but like I mentioned previously if it is increased too much fuses may blow at turn on do to increased current demand when they first charge up.To be on the safe side I would replace them with the same value.

Yes I do have some 10000uf 100volt Panasonic PC tab caps if you would like me to send you a few .Just let me know and I will send them your way.:) The only problem is you will have be creative when it comes to installing them.The can type would be easier.

jakelm

Thanks GV.

For the price I think I will just buy the can type that mouse has avaliable. But thank you for the offer.

I would like to buy all parts form one place. Mouser can fill my basket. But it seems that electrolytic caps are the only type caps they have in my size.

The Panasonic cap has a much highers voltage rating than the 16v in there right now. But since we are talking about signal path i guess voltage doesnt really matter right?

So if I understand this correctly, the uF value is what to look for as far as signal is concerned and the voltage value is what to look for as for as current is concerned right?

In other words, if the cap is in a signal path stay with the same or close to the uF value? Voltage can be as much or higher.

If the cap is in a ac/dc current path stay with the same or close to the voltage value? uF can be as much or higher value?

mhardy6647

"much higher voltage rating" is fine... just make sure the Panasonic caps will fit physically. Mouser should have links to product spec PDFs.

The Panasonic film caps are OK sonically in my (albeit limited) experience. I used some as coupling caps in a Knight (Allied) 333 (a/k/a Pioneer SX-34) due to space constraints.

Hope this helps.

jakelm

I wish I had a milimeter measuring tool, to measure the caps in there right now...so I dont screw up and buy caps that are too large for the space.

jakelm

I will take a snap shot of the board tonight, to give you all an idea of how compaqued everything is.

jakelm

The Panasonic cap is a polyester cap.

Mouser has a WIMA polyester cap 10uF 50v, which is smaller than the 100v Panasonic.