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Upgrading a Hafler DH110

I don’t see the 22uf /50v polar power supply caps having been replaced with 100uf/50v polar in the pics. Even though Bob says he did and it says it on the list. I’ll do the same. I have replaced everything suggested (but the 22uf’s, 1000uf bipolar and 470uf bipolar caps). The voltage regulators were running cool before, but warm now. The same with the transistors. More current flow ? The sound so far is not good. Greater bass and treble; have improved. I used Mundorf .47uf oils, instead. The black nichicon 4.7uf bipolar, instead of muse. 1000uf/50v polar replaced with 2200uf/50v. Deoxit inside the push switches and pots cleared balance,low sound, sound cut off issues.... Hoping the rest of the recapping will improve sound.
 
on the pwr sply replaced the 22uf polar for 100uf polar and the sound detail has improved significantly. bass and treble are significantly increased and can be noticeably controlled. the voltage regulators and trans have cooled down. will do the 470uf Panasonic polar caps next(arrived today). listening to Kenny Burell. the volume control can be dialed 2-3 notches and it is loud with B&K St 140! sounds good. hoping the sound detail improves.
 
Oh yeah! 3 dimensional sound now with the 470uf caps installed. A significant improvement in clarity. Can’t wait to do the 22 and 1000uf bipolar caps.
 
finished the recap and it's quiet now, no hiss, static, quiet, clear. lots of treble and bass to spare. The echo was from an mp3 track. thanks Bob. will replace the voltage regulators next and call it a day with lots of music
 

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I just replaced the 2 yellow .47uf caps between bass and treble controls with tropical fish versions and sound now is amazing! old ones read .45uf with high esr.
 
tried replacing the 2 yellow .1uf/100v caps by the pwr supply with panasonic metal polys and the imaging and sound quality was Killed! put them back in and viola, it's back! maybe needed a break in with the panasonics. will try Russian pio's on the .015uf blue caps between the balance and treble knobs and WIMA caps next.
 
@raycarr00 , did your DH-110 sound light in the bass section too before doing all of this? I just got a 110 the other day, hooked it up, and although the detail is great, it seems like it’s about half the low end bass it should be,and I have the bass control turned all the way up and tone button in. Did the improvements you made above enhance the bass output?
 
on the bass, I did notice that if you use the green BP Muse Nichicon caps, as apposed to the black BP Nichicon caps(as in the pics above), the bass is not as pronounced. Try black BP Nichicon caps or even polypropylenes for more bass. 4.7uf/ 25v.
Upping the capacitance of the power supply caps (as Bob did), may have increased the bass.
I did up the capacitance from 1000uf to 2200 on the power supply caps.

The most significant cap change for me was on the .47uf yellow block "cheese" looking caps. I used the tropical fish variety, which is all I had at the time, but was impressed.
Changing the two yellow .1uf caps, kills the sound. Possibly because of a cap break in?
On the 470uf caps, I used polarized Panasonics per the manufacturer.

I bought a second DH 110. The board is the first version(A versus C) and has surface mount caps in its architecture that can easily be replaced with electrolytics or polypropylenes. It also sounds fantastic!
 
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Note the revision on the board before using schematic A, B, C, D...caps are .082uf instead of .47uf, etc...on A revision; large yellow polyp. in D rev.
 
I've just completed the "Bob-list" of e-cap replacements. I've also changed out the voltage regulators and related 8DIP, along with 9 diodes (D1-6, D8-9, D11). The thing worked on the first try, no smoke, no explosions. (I don't trust it - its planning something, I just know it.)

Now the big issue is the noise in the quad buttons. I decided to bump up the bass, so I punched in the TONE button, and there was a horrible sounding transient that hit my amp and speakers. It was way louder than the music I had playing. It sounded like if I had a record playing on my big system here, and I dropped/dragged the needle. Or it was like a needle running over a scratch in the record. I mean it made me jump, and my wife in the other room was scared by it. (Next year I think I'm going to add this preamp to our Halloween decorations).

This is one of two things: either the switches are dirty, or else the caps on the little PC-13 board behind the switches are bad. Since the volume of the noise was so much louder than the music, I'm leaning towards the caps. Perhaps its a DC spike that would otherwise be knocked out by those caps? Or am I not understanding what these things are doing?

If its just dirty switches, how do I get Deoxit into them? They look pretty well sealed up. Also, which Deoxit - should it be F5?
 
Yes,replace the caps on that board or it will continue to act up,as it was doing to me;no longer a problem,here. clean the pins that the board connects to with a swab and deoxit. flood those push button switches with deoxit and work them,let it dry. they either have tiny holes or you could shoot deoxit into it while slightly pushing button in.
man,hope your speakers weren't damaged or the cat ran away!
 
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The cats are passed out downstairs like lazy slugs! I'm more worried about permanent damage to my wife's hearing - even though she was in the next room she can hear a termite hiccup in my neighbor's house. The speakers are fine - tough old B&W DM602's that I've already repaired with better parts.

Good thing I asked you about replacing these caps right now - this is the month to buy caps, since they're on sale at PCx. I have to find some good ones to replace the two you used "trivial fish" on. PCx is out of them in that value.

Which Deoxit do you use for these push buttons? I used F5 Fader Lube on the Bass, Treble, and Balance pots, and I took the cover off the Alps volume pot and soaked it with F5. But I've seen people report here that using the wrong Deoxit in certain parts will wreck them. If I'm supposed to use D5 cleaner on the push buttons instead of F5 fader lube then I'm out of luck - I don't have any D5 here. I do have CRC cleaner and also MaxPro
 
I honestly don't fret over using a specific cleaner(but use D5),as I usually use 70 or 90% alcohol and allow to dry 24hrs(or use honey's hair drier). If the switch is particularly stubborn with static,etc.,I start with wd40,alcohol and finish with d5. crc is powerful stuff with no lubricant. stay away unless it specifies sensitive electronics.
certainly,the issue is with the caps. I have several dh- 110's and have swapped that board to determine if the issue was the rest of the pre or the switch board-it was the switch board's caps. amazon. UVP1V470MPA1TD. don't recall what the other one's were;but I stick with nichicon,elna,panasonic fc. tubesandmore has good deals.
 
I stick to Nichicon ES, KZ, and FG. If I can't find what I want for the power supply in FG, I use KT.

Thanks for the advice, btw.
 
Ray, I completely forgot to ask you about the source and tape monitor switches. What are those - carbon or copper discs wiping inside a plastic sandwich? Would fader lube be appropriate there, or should I just clean them and be done?
 
I'm about to shell out for my next cap purchase. I'm going to use ClarityCap 0.47uF 250v to replace the two Seacors at C19/119. I still have to find a replacement for the 0.47uF 50V cheese at C28/128 and the .047 50V SMD polycarbonates at C27/127. My vendor has Tropical Fish to cover the C28/128, but they're out of the fish for the 0.47uF. This is the kind of thing that trips me up - no matter what vendor I buy from, they're always missing at least one part. Which means I have to go to another vendor to buy $2 worth of parts and pay $9 shipping because I don't meet the minimum order for free shipping.
 
yes,I hate that. Try digikey for 5 bucks ship. I just replaced four .1uf caps back to orange drops and they sound detailed. unlike the yellow cylindrical polys that were a 1, as apposed to a 10 in sound detail, balance, harmony. NOS trops from the bay... see if they also have the other ones. but,if you have the budget, consider the orange drops. I've taken them out to try others and keep going back...like my honey bunny. I'm getting a set of .47 and more .1uf's. they've convinced me.
 
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