• The move to the new server is done. There are some software and database maintenance updates in process. This has us passing the hat around to help out. We appreciate any donations. Seriously, even a dollar helps. The payment page may be found here - https://www.audiokarma.org/support.html

Hi Guys! Want To See A Mess?

T

tube-a-lou

Addicted Member
Hi all,

I received this today by Fed Ex and wow I never seen so many caps
added to a Hafler 101 preamp!, I only paid $90.00 bucks for it so it might be a good
project but it surely needs help.

Have you seen so many caps by-passed holy cow.

A7B17CE5-D807-4F22-8CB4-91520BDB294F.jpeg E7601748-F9AB-4B6B-AACA-0587EBBB559E.jpeg
 
Last edited:
Register to hide this ad
I sent a email to the Seller, he has a thirty day return on it, which I might
do. I haven't decided yet, does anyone here have any good pictures of their
preamp that you could share?
 
Bypassing electrolytics with low uF film caps is the in thing, didn't you know?

You can probably just remove them. I don't feel they make any difference one way or the other, and so long as they don't have long leads are not an issue -- which is why I would take them off. All those signal antennas just looking for something to add to your rails or signal path.....
 
Pio1980 said:
Easily worth what you paid, and easy enough to reverse engineer if you think it's not right.
Click to expand...
You guy's think I did good on it, I was going to send it back I have to pay return shipping, now after seeing what you guy's think
maybe I should keep it and just take everything out and rebuild it
 
Yes, it's a train wreck. As mentioned already, long capacitor leads, whether a bypass cap or just a large film replacement, can cause issues as explained on Rod Elliot's site and discussed in depth by some knowledgeable people at DIYaudio.com. I am also not a fan of the jumbo speaker-sized wires running from the RCA jacks. Other than those things though, it does look good.
 
How's this look, it looks a lot better cleaner, I added 10uf 50volts caps like in the schematic and
added wires to the outputs replace the 220 ceramic with Wima 220 caps still have to wire the phono
section have to figure out how that's done. Doesn't anyone have any pictures of the DH-101?


BE3B6B0F-228F-47A5-8E35-80CC82562B8A.jpeg 7A4DD3BE-FCC9-4A00-8967-6E3904042180.jpeg
 
tube-a-lou said:
How's this look, it looks a lot better cleaner, I added 10uf 50volts caps like in the schematic and
added wires to the outputs replace the 220 ceramic with Wima 220 caps still have to wire the phono
section have to figure out how that's done. Doesn't anyone have any pictures of the DH-101?


View attachment 2524064 View attachment 2524066
Click to expand...

I never understood bypass caps. the math on parallel caps is easy; C1+C2+C3=Ctotal. You are changing the value of the equivalent capacitor. What do they think they are improving?
 
tube-a-lou said:
How's this look, it looks a lot better cleaner, I added 10uf 50volts caps like in the schematic and
added wires to the outputs replace the 220 ceramic with Wima 220 caps still have to wire the phono
section have to figure out how that's done. Doesn't anyone have any pictures of the DH-101?
Click to expand...

You really should have done as Pio1980 (and @cademan ...missed that first time through) suggested and verified that it worked before diving in. Maybe you did, I don't know... :dunno:

---make sure that the caps removed were acting as bypass caps, and that the original electrolytics are still there. It is possible that some of those big film caps were acting as replacements instead of bypass

---ceramic caps come in different types with very different characteristics that have different roles in an amp. In some of those roles, ceramics (of the specific type chosen by the designer) are the best type. Unless you know for certain the role of the cap, and thoroughly understand the circuit, it is probably best not to try to "upgrade" ceramics.

---I am fairly sure that pics of DH-101 are online and could be found with some serious searching.....just in case no one posts them here.
 
Last edited:
You must log in or register to reply here.
Back
Top Bottom