Modding my ARC Ref Anniversary

[ayreman]

Can you give me the source of the fuse holders?

The model you want is ???4-2?. You can buy from here:

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[ayreman]

I'm interested in your comment regarding Mundorf classic Silver/Gold/Oil versus Audyn, you really found the Audyn significantly better? The TOTL Mundorfs are remarkable as it is.

Indeed I found Audyn True Copper Max caps much better than Mundorf SGO. This is hardly surprising because any copper foil cap outperforms the best of the best film cap. Copper (or silver) foil caps is the way to go!

 

[ayreman]

My RefAnn is undergoing another phase of modding. This time I'm adding 0.33 uF Duelund JDM Copper Foil caps bypassed by 0.01 JDM Silver Foil caps (see pics attached) to +/- 5V and +/- 15V in the preunit. My engineering is right in the middle of it as I'm writing this.

 

[justubes]

Looks so familiar

I have bypassed mundorf electrolytics, but did not add a silver foil to each. There were already Audyn plus caps originally bypassing the power supply caps, but just left them in.

Wonder if it is worthwile removing them since there were 1.5uf + 0.33uf x2 as bypass originally.

In previous use of Ag bypass, i did notice more attention or even a slight highlighting of the highs and removed them which actually sounder more balanced over the while range with a slight loss of attention to the highs, gthebstage was also moved forward with the AG bypass caps.

 

[justubes]

I do make it a must that 1 change must be evaluated at a time, finding more ofter than not, high quality parts wires so drastically change the sound/ improved details, clarity, refinement in many areas, but many a time also loses some heft, weight and boogie factor on lesser quality recordings.

 

[ayreman]

My engineer has finished the job (see pics attached) on my RefAnn. This was the last mod. Nothing else is planned.

 

[Joostp]

Nothing else is planned.

Sure, you said this before as i can remember........

Looks great, let us know what it sounds like.

 

[ayreman]

Nothing else is planned.

Sure, you said this before as i can remember........

Looks great, let us know what it sounds like.

What I meant was nothing else is planned to mod in the RefAnn. But I do have a few ideas about my DAC and power amp;-).

It sounds like I don't have a system. Nor does it sound like a recording. It sounds more like musicians came to my room, set up their gear and started to play for me. It's worse than drugs. I can't stop listening to my system! Bloody addictive...

 

[ayreman]

I got hold of some 0,56 uF Copper max caps for my LS27. Size was a problem so i had to install them upright.
It is a step forward compared to the 10uF Mundorf Evo's i had in there which souned a bit bright

Before i installed them i used my new 'break-in device' (courtesy of hificollective.co.uk) to treat them to some 80 hours of music.

I also noted a 1uF bypass cap (next to the red Wima's) that looked odd and it turned out to be broken so i replaced all the 1uF caps with Elna Silmic's.

Next week a friend will bring his unmodified ARC LS28 for comparison and i am very curious for the result.

Joostp, I have 2 questions for you:
1. What are those black thingies you have on top of the electrolytes?
2. How did your friend's LS28 sound compared to your modded LS27?;-)

 

[Joostp]

Joostp, I have 2 questions for you:
1. What are those black thingies you have on top of the electrolytes?
2. How did your friend's LS28 sound compared to your modded LS27?;-)

The black 'thingies' are damping pads, ARC places them on some caps to damp vibrations and i placed some bitumen pads on all the caps.
You can get it here: https://www.audiophonics.fr/en/damping-c-197.html.

The comparison with the LS28 still needs to be planned, busy with work and the Covid thing.

What did you exactly do with these new caps, how did you wire them? Replace every Wima with a new cap of the same value and a bypass?

Also i have another question maybe someone can answer: In my REF75 there are 2uF coupling caps (the golden coloured ones). I would like to replace them with Copper max caps. How critical is this value. Would it be ok to replace these with 2.2uf or 1.8uF?

 

[ayreman]

What did you exactly do with these new caps, how did you wire them? Replace every Wima with a new cap of the same value and a bypass?

Have you read my post #123? I thought I was clear about where the new Duelunds went. How exactly they are wired I can't tell you. Only my engineer can tell you that. Too complicated for me

Regarding Wima. No, you won't be able to replace all Wima with the same values AND bypass. Impossible. Just choose the largest value you can physically fit in there. Sonic benefits will be there anyway because quality is a lot more important than capacitance. If you want to use ATCM and replace ALL important Wima positions, 0.47uF is the most realistic size. That's what I used (under the PCB).

 

[ayreman]

Also i have another question maybe someone can answer: In my REF75 there are 2uF coupling caps (the golden coloured ones). I would like to replace them with Copper max caps. How critical is this value. Would it be ok to replace these with 2.2uf or 1.8uF?

Joostp, the answer to that is very simple: the more - the better. If 2.2uf fits in there - great, go for it! Oh, and while you're at it, throw out that Nichicon rubbish and replace with Mundorf with larger capacitance. You won't recognize your REF75 after that because it will steamroller REF160!

 

[Golum]

After reading this thread up & down several times and being quite extensively in touch with @Joostp, as he has the same power amp, I decided to do the "refresh/mod" of my Ref75. Final trigger point was decision or actually no intention to sell it in the foreseen future due to great performance as such, and tbh I do love ARC and the look of this particular unit.
Beside reading this thread I've also been in touch with few friends who are extremely "in the know" as they are deeply into DIY and I also consulted a friend from the industry.
So in nutshell, I did not do the massive upgrade as Ayreman is doing, but rather I did the following. Exchanged all power caps for Mundorf MLytic, replaced stock coupling caps with VCap ODAM, exchanged all resistors on the signal path with I would say top notch ones or close to top notch and lastly all the resistors around the power tubes. Signal wire going from input to PCB board was exchanged as well. As previous set of tubes had like 2.5k hours on them new quad of KT150 is being used and instead of 6n30 we've plugged in 6n6p gold grid (super close matched) military version with red tip.
Majority of stuff replaced, I would say is not questionable, but some might ask why VCap ODAM. I spoke with Lukasz Fikus who tried majority of existing caps and he was like don't bother too much get VCap and enjoy and BTW don't bypass it.
Point is also that I want amp to be fast, open, detailed and not really tube colored as upstream all my gear is with DHT tubes so I don't need more "flavor" in the chain.
Anyhow, I did not do the job as I'm clueless regarding electronics and even soldering, so I gave the job to the person in the know, who also used to be appointed ARC service person in CH. Not to forget - parts values were not changed - I was looking for exact same values as per original schematics and service manual.
Amp is done and I'll pick it up these days (quite a drive to do so) but the person doing it commented: "I've never heard ARC sounding this good" and "This has nothing to do with your "old" amp"...
Fingers crossed and looking to get my good old amp back in the shelf. Few pics for illustration...

 

[audioguy1958]

The Mundorf Mlytic and VCap capacitors should be a huge upgrade. You will need an extensive burn in, 300 to 400 hours. How are you going to burn it in, hopefully with frequency generator 20Hz to 40KHz? Are you using a resistive load as well?

 

[Lampie519]

In this case i would replace the tubes first (putting back the old ones)...

 

[Golum]

The Mundorf Mlytic and VCap capacitors should be a huge upgrade. You will need an extensive burn in, 300 to 400 hours. How are you going to burn it in, hopefully with frequency generator 20Hz to 40KHz? Are you using a resistive load as well?

Funny enough I was discussing exactly this "issue" of burn in with one of my friends today and he proposed this exact thing...but I guess I might use just normal burn in process with all its ups & downs but with old tubes (still working normally)

 

[Cellcbern]

Hope you get the results you were seeking. I am a big believer in upgrading a component you really like the sound of as evidenced by my 2nd upgrade of my Pathos TT RR (posts at this site). For others considering such upgrades, I've found the Humble Homemade HiFi capacitor comparison useful in deciding which caps to use:

Humble Homemade Hifi - Cap Test

Humble Homemade Hifi - Very high quality loudspeaker kits, components, upgrades, modifications and custom solutions.

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[audioguy1958]

I would not recommend burning in by leaving it in your system, this could take several years. By burning it in on the bench you can be done in two weeks, and believe me the difference after the burn in period is a complete is a revelation. If you try to listen to new electrolytic caps without any burn in it will make you wish you hadn't bothered. If you would like to know what equipment to buy for a bench burn in just pm me, if you don't have it already.

 

[Lampie519]

Maybe he likes to listen to Nine Inch Nails, then the burn-in time is reduced to 1 week...

 

[ayreman]

Golum, nice to see substantial modding of your amp and I fully agree with comments of your tech who did the work. You now have a brand new amp that outperforms anything that costs 5 times that (and I mean including what you've spent on new parts and the modding work).

Audioguy1958 is right - the burn-in process ahead is going to be long and nasty. And indeed there will be days when you'd regret the whole project. You'll have to be brave, grin and bear it. Joy will come back after 600 hrs. I've been through this many times over and I did not like it one little bit. But joy never failed to come back!

Well done!