Hello all

[shep]

Just been busy as H. and as you may remember, doing a serious cosmetic upgrade to my cdp. Pictures were promised and will be forthcoming. On an entirely dif. subject; you may remember that my neighbor has a 25+ year old Audible Illusions pre. that came from me back then. It's been decided it needs attention... as in new caps, better resistors, removal of the phono circuit and better quality rca jacks. I'm sussing this out for him. Anyone have a good address? not expensive, reliable etc. It's pretty light so could be shipped to the states I suppose.

[shep]

HELLO? Empty room... everybody out raving?

[richidoo]

Hi shep!   

CDP pics   

I would sell the preamp and buy another one rather than modding it. It's value doesn't warrant putting a lot of new money into it. Why pull the phono section?

[rollo]

  Shep our club modder, service tech and designer Scott of S&G Custom Sound in NY can and is familiar with the AI pre.
  Now this Pre has it ever been demagnetized ? How old are the tubes ? The Ayre/Cardas demag CD is a must use as well as the Gryphon Exorcist . As so many of our club members have experienced a new life to their system just by demagging. New tubes as well should be considered before plunging into mods. The AI is very hard on tubes. New tubes really make a difference for the good. I owned a AI 3A for a long time, believe me I know.
  If he still wants to mod it choosing caps and resistors that will not change its character will be a challenge and gamble.
  If it were me I would  try the above first. Or as Rich suggested  sell the AI and look elsewhere. A Nightshade Beacon can be had for around a $1000. BTW Agon is flooded with used preamps. Cash is King.


charles

[shep]

Well...a. it's not mine to sell b. it's been re-tubed recently and it didn't eat tubes for years and years. c. he doesn't want or need the phono section. It's never been demag'd. If this gets too complicated I will tell him to keep it as is. I don't want to spoil someone's pleasure with an ill-considered mod but it seemed to me fairly simple and straightforward.

[tmazz]

+1 on the demagging.

I do my entire system on a regular basis as part of my general maintenance and cleaning routines.

[richidoo]

The reason I ask about the phono section is that most preamps with unregulated power supply share power supply with the phono stage. If you disable the phono stage or leave out the tubes, then the powersupply circuit is changed and affects the linestage voltages.

You bring up an interesting question. Is the tube eating reputation due to the original design or due to the aged condition of older units?

[shep]

All I know is that it had the same tubes as when I bought it new, so that would be about 25 years. It finally started to sound a bit off and he re-tubed it with some russian tubes he bought here and it sounds and works just fine. Wasn't it the later versions that had a bad rep.? I have a feeling that you are right about the phone section being virtually impossible to remove with out a silly re-build.

[Carlman]

If he has a Modulus 2-d or 3-, he has one of the finest phono sections I've ever heard.  Modifying it will likely be a turn for the worse.  I found Bugle Boy's and the Russian tubes with little rocket logos to work extremely well in my old AI... I had a modified 2-D that burned through tubes faster than the stock unit.  The AI might be a little noisy but I'd be careful about any significant mods.. a cap replaced here and there is OK.. but circuit changes are likely to be a long road to nowhere.
-C

[rollo]

 OK then the 25 year coulping caps for input and output would be a good start. Key resistors as well. RCAs if ya like however I would use that money for NOS tubes like Amperex Bule Boys or Telefunken.
   The existing circuit is a classic and IMO should not be fooled with. A V-cap Teflon [ input] followed  by a Deuland " Alexandra" PIO cap [ output] will make her sing. Kiwame or Takman resistors will do the trick as well. In the power supply todays rectifiers and diodes are a big improvement over the originals .
   Have fun.



charles

[shep]

Thanks for the input. I may regret this though! Too many options and it's not even mine. I haven't looked at it closely but it must be an early Modulus, with two vol. controls (a right pain in the ass that is...no indents). It's even a 110 v version (using a step-up transformer I bought with it) If it were mine I would happily sell it to "you", but it ain't. He's leary of spending too much but someone did PM me an address in the states which looks promising. Here's the letter I got;

"Hi Shep,
 
There can be different options  you can try for upgrade.
 
1) Upgrade output coupling capacitors to better grade, and some resistors.  Cost should be $150 to $200 depends on the grade of capacitors
2) Upgrade output cpacitors to better grade, and some resistors, RCA jacks, filter capacitors.  Cost should be about $300 to $350
3) Upgrade output capacitors to better grade, some resistors, RCA jacks, filter capacitors, volume control, better diode.  Cost should be about $380 to $430.
 
I will perfer option 3 as the volume control affect the sonic result very much.
 
Thanks,
 
Karl"
Obviously have to factor in shipping. But if it comes back not to his liking I will be in the Sh...t. I don't mind taking the risk with my own stuff...I have a pretty lucky star, but with some one else's....different story. He has long up vinyl (I know, we're hateful, us CD people) so whether or not it has a great phone section is irrelevant. I think I should have kept my mouth shut and not proposed this for him