oops.
@tube-a-lou , if you need more help with the 101, please post your questions.
I did find another pic of my dh-101 board. I replaced c2 with a bipolor MUSE and c3 and c4 with FG. Probably got the info from Bob's link above.
Hi Guys! Want To See A Mess?
- Thread starter tube-a-lou
- Start date
oops.
@tube-a-lou , if you need more help with the 101, please post your questions.
I did find another pic of my dh-101 board. I replaced c2 with a bipolor MUSE and c3 and c4 with FG. Probably got the info from Bob's link above.
Pio1980
AK Member
Iirc, this was Haflers first offering under his own name, a budget decent performing preamp kit basically designed, I'd read, by Gates, of broadcast and studio gear.
Remember it's a budget effort, improvements and upgrades are possible.
The function switches can become troublesome in time.
Remember it's a budget effort, improvements and upgrades are possible.
The function switches can become troublesome in time.
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I haven't had a problem with the switches but the pre is built at a price point. IMHO, the switches and rear input jacks are the weakest point. I actually built a homebrewed dh-101 without tone controls, better selector switch and rear input jacks. I used it to control my rear amp/speakers in my cobbled together 5.1 setup. I've since pulled my SACD player and related HT gear (including preamp).
Someday i'd like to add a raspberry pi streamer to the pre and put it back into the system.
maxhifi
Addicted Member
Electrolytic capacitors have characteristics which vary according to frequency, due to internal inductance, effectively increasing the impedance as frequency rises. The idea of a bypass capacitor is to reduce this impedance rise by paralleling a smaller, lower inductance capacitor which has a lower impedance at higher frequencies. This topic is somewhat controversial, but high end equipment which sounds excellent often employs bypass capacitors, so it isn't completely crazy to try and mimic this technique in an effort to upgrade lower end equipment.
I have noticed in the case of loudspeaker crossovers, which are particularly sensitive to the impedance of capacitors, that a small value bypass capacitor can have clearly audible consequence.
In other words, the small change in the capacitance value isn't the point of bypassing, it is the change in the impedance versus frequency curve which can have a subtle impact.
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Lavane
Lunatic Member
I've been using Faderlube more and more lately. I had been using MG chemicals
Contact cleaner more than Deoxit. Faderlube does seem to work better.
A couple pieces of equipment had to have the pots cleaned again later after using Deoxit. After using Faderlube, they have stayed noise free, and feel smoother. I first used it on sliders and reallyiked the results.
And for so long I thought it was only meant for sliders. Guess that's why I came to AK.
tube-a-lou
Addicted Member
I'm having a bit of trouble cleaning the pot's should I desolder them and remove them.
D5 is for metal contacts, not carbon. Faderlube won't damage carbon tracks.
Dogum
Livin' the dream, then woke up...
Be sure to check the preamp RCA jacks on the back board for good contact. I had to give mine a squeeze with the needle nose pliers before both channels worked properly. These are not the best design and are easily spread and they will corrode.
I would be interested as well as to how the original sounded! There was a reason someone went to the trouble to put those caps in, but the workmanship is questionable.
You got a reasonable deal, even with the extra effort. I have no understanding of the prices asked on eBay. These preamps sound good for what they are but not amazing.
I would be interested as well as to how the original sounded! There was a reason someone went to the trouble to put those caps in, but the workmanship is questionable.
You got a reasonable deal, even with the extra effort. I have no understanding of the prices asked on eBay. These preamps sound good for what they are but not amazing.
tube-a-lou
Addicted Member
Oh boy here we go, I received the new Hafler DH-101 today and plug it in just to try it out
and the right channel is fine but there no signal in the left, I turn the bass control and it just
thumps and there's a low level buzz also in the left channel. Two in a row I'm not doing good
this week. I'm going over it now and will check the solder joints some look kinda weird and by
the way it's not been modded, it's odd both of them when I turn the bass control it thumps in
the left channel, caps, transistor's or ?????
and the right channel is fine but there no signal in the left, I turn the bass control and it just
thumps and there's a low level buzz also in the left channel. Two in a row I'm not doing good
this week. I'm going over it now and will check the solder joints some look kinda weird and by
the way it's not been modded, it's odd both of them when I turn the bass control it thumps in
the left channel, caps, transistor's or ?????
yikes! That is disappointing.
To bad you are not closer, we could throw it on the bench and we'd get both working. they are pretty easy to repair.
clean the external patch to/from jumpers too (I think mine are permanently soldered together since I'm not planning to use an EQ).
Rectilinear1
Professional Record Restorer
Why do you say that? I have used deoxit for years on hundreds of pots with perfect results. Trust me, I'm a pothead! Faderlube is for faders my friend. Now, do NOT use deoxit on faders. It will destroy them. Cheers!
So how does one tell if a pot has carbon contacts? Is carbon the norm for some items? Or Faderlube works on both so can be considered universal?
There was an AK thread a few years back where even a Caig company representative said that it was probably best not to use D5 in pots, and suggested F5 or D100 (which lacks solvents). And there have been more than a few cases where individuals post that their pots were damaged by D5.
"A smart man learns from his mistakes. A wise man learns from the mistakes of others."
In the majority of cases where D5 is used in pots, it may be likely that no harm is done. But to actually know that no harm has been done would require opening up the pots and performing an objective and scientific analysis. Who has done that? Even if a pot seems to be working fine, it could have sustained damage to the carbon film, or to an adhesive, or to lubricants, that might have lessened its useful lifespan, or might not show up until some later time.
The argument " I have done such and such x-many times for x-number of years and....whatever" is meaningless. It proves nothing.
"A smart man learns from his mistakes. A wise man learns from the mistakes of others."
In the majority of cases where D5 is used in pots, it may be likely that no harm is done. But to actually know that no harm has been done would require opening up the pots and performing an objective and scientific analysis. Who has done that? Even if a pot seems to be working fine, it could have sustained damage to the carbon film, or to an adhesive, or to lubricants, that might have lessened its useful lifespan, or might not show up until some later time.
The argument " I have done such and such x-many times for x-number of years and....whatever" is meaningless. It proves nothing.