Hafler TA1600 recapping... looking for more bass

[JohnnyP00]

Hi,
I have a TA1600 thats starting to give off some hissing like a waterfall so I'm going to try to recap it. I'm a newbie to diy amplifiers but have a little knowledge. I'm thinking of recapping the unit but was wondering if it were possible to increase the bass response. If I increase the main caps uf would that help? I've noticed a deterioration in sound and also the bass is becoming almost non-existent. I have the scematic for some reference but it's too big to attach. These are some other things I would like to try in the future:
1)Putting a cap on the on/off switch and power and also putting a cap on the iec.
2)Removing the volume pot all together or find a way to bypass it.

It's a cheap little amp so I'm not afraid of ruining it. I thought it would be a good amp to start my diying on it. Thans for any help...JohnnyP.

[djk]

"bass is becoming almost non-existent"

First thing to check is the big cap in the feedback loop to ground.

[HaflerFreak]

Hi, I am definitely not an expert on this subject, but I do own a Hafler amp, and I do have a similar 'lack of bass' experience.

djk is right, on my amp, it is a 6.3V 1000uF cap.

If you do not already have a .01uF 1KV ceramic across the power switch, put it in (and replace the power switch if necessary).

The only other thing I have to add here is that it could also be your big main caps showing their age. Testing for ripple is a good first step.

[techgadget]

Hello to all. I am a newbie to the site although I have followed many of the posts on various forums for quite some time!

I also have one of the Hafler TA1600 amps. I just picked it up as a running amp but although it works it have pretty low output on both channels and next to no bass output at all. Any idea where I should start on this? I checked the output voltage on both of the large 3300 caps it is 41VDC. Nothing appears to have physical damage. Any chance someone has had this problem as well and figured out what is wrong? Also any chance someone may have a service manual available?

Any suggestions would be greatly appreciated, Thanks!

[rylon]

Sorry to bring this back from the dead but Im having this exact same problem. bass is very weak and the mid-highs sound overdriven and practically hurts to listen to. Any suggestions? i'm going to to try to bust it open and look for blown fuses, and I'll try to identify the feedback loop transformer like someone mentioned. Any help is appreciated.

[Zero Cool]

I have not seent he schematics for the 1600 but i am working on a TA-1100 that i bet is similar. I found lots of bad Electrolytic caps on the amp boards! the amp sounded overdriven and had visable distortion on a O-scope. there is an Op-amp with two caps back to back that connect from the negative input of the op-amp to its output forming a filter. this is connected in the Negative feedback loop of the amp. the back to back caps were bad causing an open loop condition in the op-amp and this was then injecting distortion into the NFB loop of the amp!

Check all the El caps in the amp. I bet you find a bunch of bad ones!


ZC

[techgadget]

Hi, I am glad to see some interest in this thread again!
I had so many other projects going that I had just put the 1600 aside waiting for the schematic or some suggestions. I have yet to find a schematic for this model. If anyone happens to have one or even one for the 1100 model that would be greatly appreciated. Sounds like checking all the caps would be a good start. I will post any findings here after I check them out. Thanks for the suggestions.

[JohnnyP00]

I have a schematic but its too big to post. If you pm me your e-mail I could send it direct... JohnnyP.

[rylon]

Im too new to email, but i would like the schematic. Please mail it to "iplayintraffic2(at)gmail,com" Thanks.

Techgadget, it reads like our problems are identical. Do you have piercingly loud highs and mid-highs, with almost no midrange or bass? Sometimes the highs sound mudded together or "waterfally." Also as i increase power, it seems like the lows stay at a constant volume while the highs increase dramatically. Also for some reason it seems very quiet unless i give it a heavily preamped signal. Line level or headphone out should be sufficient for this correct? Sorry, Im new to this style of power amplifier.

Does anyone know if JohnnyP00 ever recapped his or got his working?

[rylon]

Oops i wasn't paying attention. Johnny did you ever make an attempt at recapping or get your bass output working correctly

(sorry for double posting, guess i cant edit yet either)