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Upgrading a Hafler DH-100

Hey guys,
first of all I wanted to thank you all for the great info that you guys posted here. I purchased my DH-100 not long ago and love it. Started changing the resistors and the opamps, but didn't notice that the ones recommended here were
Metal film 1/4W 1% resistors 22.1k and 1.1k ohm

I have 2W ones and the sound is really sharp. Is it possible that its related to the wattage difference and to the fact that I got not metal film but carbon ones?

Thx for your help :)
 
The wattage shouldn’t matter but the resistor types might. People say they prefer one type over another but I haven’t compared different types in the same unit.
Also maybe the op amp sounds slightly different? I’m not sure, I haven’t changed mine yet. Both my DH100 are recapped and I removed the muting circuit, but are stock besides that.

Bob really helped me dive into my Haflers, but it looks like he hasn’t been around for a while now.

@Raph1978
You could always start a thread asking about resistor types or one op amp versus another. Sometimes people don’t chime in on threads like this unless they have experience with the unit in question, but if you’re asking about certain parts they might have experience with that.
 
Hi @elitopus , thx for your response. I managed to purchase the proper metal film 1/4 W resistors and replace the carbon ones. The previous ones were 22k and 2W not 22.1k 0,25W. Somehow the difference is just mind blowing. The sound with the metal film ones is more delicate but at the same time more detailed. What I mean is that the treble is not as sharp / ear piercing. I must say it was worth driving to a shop 45 each way in the middle of the pandemic to get them ;) I strongly recommend the change as it makes a world of difference.

I'm also wondering about the different opamps. I got the NJM5532DD from JRC. I have no idea what does the DD stand for, but I also found P, N and AP ones. Any idea what's the difference between them?
 
Raph1978 said:
Hi @elitopus I'm also wondering about the different opamps. I got the NJM5532DD from JRC. I have no idea what does the DD stand for, but I also found P, N and AP ones. Any idea what's the difference between them?
Click to expand...

You can look up the data sheet, Digikey and Mouser usually have them online

https://www.mouser.com/datasheet/2/294/NJM5532_E-1917664.pdf

The first D refers to the packaging, in this case a DIP8 package which is what you want.

The second D indicates it is a D rank IC. D rank indicates it was sorted by the manufacturer for superior input noise voltage performance. This is also what you want for this manufacturer.

I plan on using the same JRC part as well for my DH-100 upgrade. I'm having more issue identifying the caps I want to use.
 
Rocketboy said:
You can look up the data sheet, Digikey and Mouser usually have them online

https://www.mouser.com/datasheet/2/294/NJM5532_E-1917664.pdf

The first D refers to the packaging, in this case a DIP8 package which is what you want.

The second D indicates it is a D rank IC. D rank indicates it was sorted by the manufacturer for superior input noise voltage performance. This is also what you want for this manufacturer.

I plan on using the same JRC part as well for my DH-100 upgrade. I'm having more issue identifying the caps I want to use.
Click to expand...

Thank you for your help and sorry for the late reply.

I wanted to share with you where I found my caps.

When choosing my caps I decided to use First Tier Caps from Toms Hardware Guide:
https://www.tomshardware.com/reviews/power-supplies-101,4193-5.html

Kind made it a no brainer :)

The JRC sounds very nice, although I'm still wondering if getting original SIgnetics op amps wouldn't be better. They cost significantly more (around 10-15$) in Europe. I wonder if there's anyone here that got to try out both of them?
 
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