Modding my ARC Ref Anniversary

ayreman

Well-Known Member
Jan 2, 2017
190
52
93
Ukraine
#61
Question: Are the many smaller ones so fast that they could compensate the size or do like a more relaxed sound?
Hi GS-Maxi,
To answer your first question... The uF of the coupling caps you need in a preamp depends on the power amps you use with it. Since I use my REFAnn in tandem with Ayre MX-R Twenty, what I have now in coupling caps is more than enough. Also, what I discovered, is that quality of the caps is much more important than quantity...
 

ayreman

Well-Known Member
Jan 2, 2017
190
52
93
Ukraine
#62
Will you do the resistor matching in the next project step and when will it be?
No, at this stage I have no plans to replace resistors in my preamp. One has to stop somewhere...:)
 

ayreman

Well-Known Member
Jan 2, 2017
190
52
93
Ukraine
#63
Third Question: Did you change the bypass cap of original 0,0024 uF cause I can’t see or is it the black one which seems bigger?
Of course I changed the bypass caps too! I replaced them with Duelund 0.01uF 600Vdc Silver (Ag) Foil & Wax/Oil Precision BYPASS Capacitors. On the photos you can see them right next to the Jupiters.
 

Attachments

ayreman

Well-Known Member
Jan 2, 2017
190
52
93
Ukraine
#64
Second improvement is of course (!) to get all the important (not all) Rectifier-Diodes (20) resistors (24 x Dale) in the PSU to the same fast and precise level.
GS-Maxi, I never got round to changing stock diodes and resistors but now you got me interested. How do you identify the important ones? Since we own the same preamp and you've already done that with very good results, I might as well use "your recipe" on the important rectifier-diodes and resistors. So, can you tell me which are the important ones and worth changing (here or PM me)?
 
Jun 11, 2020
6
4
5
56
Hamburg / Germany
#65
Let me start with a pic of the development status ... here is the first one I had on my mobile, more will follow the next days, when I could take some pics of the pre section:
33DBC197-B73F-4A31-AEAE-378D3A6AE5A2.jpeg
 
Last edited:
Likes: ack
Jun 11, 2020
6
4
5
56
Hamburg / Germany
#66
Replacement with DALE 1% resistor (crucial currents to and from the tubes) and elimination of microphonics (Herbies tube dampers) and protection against floating around electrons (Pearl Hi-Fi):
ECE3DFF8-7690-438F-8EE6-33F904833AC3.jpeg
 
Last edited:
Likes: ack

Brucemck2

Member Sponsor
May 10, 2010
302
23
423
Houston area
#69
Can you post a link to those AS-75 terminating plugs?
 

ayreman

Well-Known Member
Jan 2, 2017
190
52
93
Ukraine
#71
Inspired by GS-Maxi, I am in the process of replacing most stock resistors and diodes with decent stuff. Replaced Audio Note electrolytic caps with Mundorf. The PS unit is already done. Here are some pics.
 

Attachments

Last edited:
Likes: CKKeung

ayreman

Well-Known Member
Jan 2, 2017
190
52
93
Ukraine
#73
Preamp is done too. Here are some pics with the new resistors in.
 

Attachments

dcathro

Well-Known Member
Sep 16, 2016
97
60
83
Melbourne, Australia
#74
Wow Ayreman, you don't hold back!

I agree with you that you can only get to the best by starting with a really good circuit and then carefully selecting the best components.

Your pre could never be sold commercially, because of the 20x markup ratio on top of those insane parts.

By the way, I have another minor suggestion for you. Replace all the little aluminum heatsinks with copper ones. You will be surprised at the difference this makes!!

All the best

David
 

ayreman

Well-Known Member
Jan 2, 2017
190
52
93
Ukraine
#75
Wow Ayreman, you don't hold back!

I agree with you that you can only get to the best by starting with a really good circuit and then carefully selecting the best components.

Your pre could never be sold commercially, because of the 20x markup ratio on top of those insane parts.

By the way, I have another minor suggestion for you. Replace all the little aluminum heatsinks with copper ones. You will be surprised at the difference this makes!!

All the best

David
David, what little aluminum heatsinks do you mean and where can I buy the copper replacements?
 

dcathro

Well-Known Member
Sep 16, 2016
97
60
83
Melbourne, Australia
#76
David, what little aluminum heatsinks do you mean and where can I buy the copper replacements?
Hi Ayreman,

These:



I don't know of any direct commercial available replacement in copper. I make my own from copper sheet squares like these .

You don't need that much metal to act as a heatsink, so I use 3 plates, the middle one flat and the outer ones bent out to the sides for airflow. It is important to use a brass screw, as you are trying to remove any ferrous materials away from the regulators. You will notice less grain and richer tonal colours.

Cheers

David
 

dcathro

Well-Known Member
Sep 16, 2016
97
60
83
Melbourne, Australia
#77
Another option to replacing the heatsink, is to just put a copper plate between the device and the heatsink, so that the regulator is contacting with copper and not aluminum. Then use a brass screw. The reasoning behind this is the removal of eddie current in the heatsink.
 

ayreman

Well-Known Member
Jan 2, 2017
190
52
93
Ukraine
#78
David, thanks a lot for a new idea! I've PMed you on this.

My engineer has left and the system is up and running again. What I'm hearing brings me to an inevitable conclusion: quality of resistors (and diodes) in audio electronics is as important as capacitors. Very glad I did it! Low-end resolution and articulation is much better. Top end is silky-smooth. Tonal richness is better. Sound stage is deeper and the background is darker. I am bracing myself for a long a bumpy break-in period. Not the first time though. Must be brave;-)

P.S. The magnetic crap my engineer soldered out is already in the trash can. Amen.
 

Attachments

marty

Well-Known Member
Apr 20, 2010
1,808
1,021
585
United States
#79
I'd be careful replacing diodes. They can have very different specs and sometimes there's good reason for that.
I'd be especially careful replacing anything, particularly capacitors, with different manufacturers of the same printed value without confirming the exact value with a capacitance meter. I've been where Ayreman is for most of my audio life, modifying almost anything that can be opened, in search of better sounding parts. Caps are notoriously high in variance from published values. They are surprisingly often +/- 20% even if the values suggest they are +/- 5%. But even that may not be good enough, A finely tuned circuit can sound totally different with a 5% change of value from what is being replaced. If your cap value is lower than stock, its easy to piggy back caps in parallel to increase the overall value to get the exact value of the original, but if your stock is lower in farads than your replacement, then its obviously more of a pain. Also keep in mind that ideally you don't want to change the ESR when you change cap brands. Doing this work without a basic meter is simply asking for trouble. The reasons manufacturers chose what they use is based on many things; cost, sonics, size, etc. But at the minimum, you really should match the exact measured value of the original component to be replaced and not rely on the value labeled on the case, which is a potential recipe for disaster.
 

sbo6

Well-Known Member
May 19, 2014
1,063
145
285
Round Rock, TX
#80
Congrats, looks to be a monumental effort and executed with very good workmanship. I've done some mods to preamps but nothing like this. What I find is that you can only go so far in terms of improvements by changing components like caps, inductors, diodes and resistors when a large percentage of the sonic quality comes from the transformers and attenuation control. I found that at that point, step up to a better unit and mod it if you so desire or design your own.
 
Likes: ayreman

About us

  • What’s Best Forum is THE forum for high-end audio, product reviews, advice and sharing experiences on the best of everything else. A place where audiophiles and audio companies discuss existing and new audio products, music servers, music streamers and computer audio, digital to audio converters, turntables, phono stages, cartridges, reel to reel, speakers, headphones, tube amplifiers and solid state amplification. Founded in 2010 What's Best Forum invites intelligent and courteous people of all interests and backgrounds to describe and discuss the best of everything. From beginners to life-long hobbyists to industry professionals we enjoy learning about new things and meeting new people and participating in spirited debates.

Quick Navigation

User Menu

Steve Williams
Site Founder | Site Owner | Administrator
Ron Resnick
Site Co-Owner | Administrator
Julian (The Fixer)
Website Build | Marketing Managersing