Infinity IRS Beta Mods Query

[msb64]

Hi Paolo

I checked some of the dac/transports you mentioned and they do look like nice units to consider. The only setback is that even used, some of them still cost more than what I paid for the Betas. I might have to hold off on that purchase for awhile, but now you have given me some good names to watch out for, thank you very much.

In regards to swapping out the NP electrolytics:

I checked the solen.ca site and the Yellow Bennics (metalized polyester) are almost unbelievably inexpensive, but it would be hard to match up to the exact values I need with what they have in those.

Another option that they do have though which I like is the Metalized Polypropylene Capacitors. I believe I read that the polypropylene is a superior cap, plus these have a higher voltage (250V), and there is an exact match for 3 of the 4 caps I require.
The one value that do I need and that they do not have is 35 mfd, but I could make up that value with a 33mfd and 2 mfd in parallel. They do have a 36 mfd capacitor, but that may not be the best option. Please correct me if I am wrong.
All of the Solen Polypropylenes I need for both sides would only add up to about $260 Cdn or so, a small price to pay for a decent cap/upgrade in my opinion.
I will see if I can track down some new NP electrolytics of the same value so that I can do an A-B comparison. They are not very expensive and I would like to hear what the difference would be.

I am also going to use the Solen caps to replace factory caps where I can and use for bypass caps in one of the Hafler amps I am modifying.

Btw, I helped a friend win a set of Infinity RS1bs in very nice condition, a few weeks ago, can't wait to hear those too. Needless to say he is pretty excited about getting them. I will make sure he checks out the caps in his crossovers too.

Thanks again for your assistance!

[inertial]

Hi msb64,

do not worry about 35mF or 34 or 36..........it is ok the same
MKP normally is slightly better than MKT but not Because 250V versus 160V (and it is audible on the tweeter, not sure how you can expect
in a midbass............)
You can't have these high voltages on your speaker !
A-B comparision is the better thing you can make, imo experimentate
in first person is the way to go for learn.
I know Wadia are expansive, sometimes some little old models is offered ( for you lucky american and canadian guys!) at decent prices.
Wait a good offer.
There are others choices for DACs like Spectral or Threshold , Pass, but
they are expansive the same unfortunately.

Cheers,
Paolo

[msb64]

Hi Paolo

I moved the mid/high towers further away from the back wall the other day and boy did it make a huge difference. I now have them 4 feet off of the back wall and even though they take up more living room space, there is no way I will move them back.

I am still in the process of ordering parts, as well as doing some homework on components. I found some really good information on Tony Gee's website to help me decide what to try first. I even made up a set of cat5e cables as he describes and they do work surprisingly well. http://www.humblehomemadehifi.com/CAT5.html
Here is a good braiding how-to that I found to help me make them. http://seriss.com/opcs/install/braid.html I am going to track down some 23 gauge cat6 wire, and give them a try too. Here is a photo of the braided wire, with you use different colors, they have a snake skin look to them.

I will stick with the Solen caps to replace the n.p. electrolytics on the Betas as you recommended, but will make a different choice on the Hafler components. I have already ordered a bunch of Vishay MKP1837 .01 mfd caps, and will also be trying Sonicap Gen I .47 mfd and 5 mfd to run as bypass caps. All are very reasonable in price, and certainly worth trying, at least for me.

I finally got the Threshold S/350e on the mid/high towers, and although it sounds better than the S/300 series II and even the S/500e, the 80s modified Hafler DH200 still wins hands down. The soundstage is much deeper and more forward (more 3D) and it handles the upper frequencies much better. The plan so far is to work on an improved, possibly monoblock versions of the Hafler with Musical Concepts boards, toroids and additional p.s. caps to use in my system. For the cost involved, they would be pretty hard to match in performance. I haven't given up on the Threshold amps yet though, I have ordered new replacement Mallory caps for the big electrolytics in the S/500e and S/350 and will also update any other smaller electrolytics inside as well. I will then try running some of the bypass caps listed above on them to see if it helps.

I had a friend (with good ears) who is a die-hard vinyl and tube fan (Audio Research) come over and help me evaluate the changes. He ended up bringing over some cds to evaluate with and one of them really stood out. He had a soundtrack cd for the movie Apollo 13, track # 20 is Blue Moon by The Mavericks. I am not a big fan of country style music but that song is incredible. The lead singers' voice reminds me very much of Roy Orbison, and that song definitely belongs in any home audio testers collection. I ordered a "Best Of Mavericks" 20th Century Masters cd online to try and get the best possible recording I can of it. Definitely one of those "Wow" songs

[inertial]

Originally posted by msb64
Hi Paolo

I moved the mid/high towers further away from the back wall the other day and boy did it make a huge difference. I now have them 4 feet off of the back wall and even though they take up more living room space, there is no way I will move them back.

I was sure of this !


For the amps, IMO we can't make definitive choices without a definitive source. Like the old issue " before the chicken or before the egg?"
is it also true the opposite but, in your specifical case I presume the source is the weak chain.
Beta's panel are tremendous loads for an amp. The ideal imo is a big
,hot,tubes amp with appropriate 2-3 ohms " selector"output.
Not sure but something like some older CJ's .....
With solid-state you'll have always some "grain"-fatigue IMO.

For the cables, I think beta's panel works the best with solid-core cables, but I admit it is refiniments

Cheers,
Paolo

[msb64]

Paolo, you were definitely right on about that aspect, the difference is substantial, it expanded the sound stage tremendously.
They definitely need their "breathing room". It makes me wish I had even more room space to give them. More room width, height and length and then see how good they really can sound.

I agree with you 100% about having the best possible source, otherwise one may ending up choosing components downstream that mask or hide the source's deficiencies.

The Arcam player does have digital outputs to allow for a separate DAC, that may be a way that I can make the transition to a better source when funds permit.

I myself was thinking along the lines that it would be nice to have a tube preamp, a solid state amp on the bass towers, and tube poweramps on the mid/high towers.

I remember reading somewhere that Arnie Nudell stated that the IRS and IRS Betas where designed to be operated with Audio Research tube equipment, and I am pretty sure he knew what he was talking about. My friend is determined to track down an AR preamp and monoblocks, maybe when he gets them I can convince him to bring them over (with his turntable) for an extended test session. I have a feeling though, that I may not want to let them go

Thanks again for your input, it hasn't fallen upon deaf ears
Mike

[inertial]

Hi Mike,

Hey, it is a pleasure for me to help other diy passionate
Forum is a strange place. You can't know who is from the other side of the screen . English is another problem, talking about with a "unknow" that write as a 5 years baby is not the best thing I believe.
Skepticism is guarantee
But I am confident things can go bettewr in the future.
Normally I talk only about things I know perfectly , things I have direct experienced in my system ( in the last 20 years).
Plus I have very good ear and my methodology is rigorous.
If I am not sure I advise, no problem on this.
Back to your Beta's, I believe CJ or Manley can be better match than
Audio Research. You need soft, hot, sweet watts
But the output "selector" in the output transformer is very important.
If I well remember, stereophile reviews showned a terrible impedance graphs, imho 4 ohm selector is not optimal. 3 or 2 ohm will be better.
Personally I don't think you need tons of watts, only the right output adapter.
Similar is for the preamp, the last generations of CJ is very interesting
as like an old Audible Illusion ( even more cheap!).
But Mike, don't you have a friend who have a minimum of skill with tubes? A line level preamp is "elementar", it is a game for boys make a basic 6N6 or ECC99 common cathode output.... and it sound perfect to match with your Infintys IMO.
Anyway maybe I'm going OT .

If your friend can put his turntable and his AR amps it will be a positive thing. Direct experience do not have soubstitute!

I was forget the arcam. Yes you can use it as a player and connect with external DAC.
Some people report very good things about Lite DAC 60 or 72.
They have near minimalistic tube output stage and good BB dacs.
Cheap also. I am thinking to take one and modds

Cheers,
Paolo

[msb64]

Hi Paolo

I checked out the Lite Audio DACs and they do look very interesting and relatively inexpensive too, as you had stated. Thanks for letting me know about them.

The Lite Audio DAC AM solid state unit looks interesting, but I figured I would give one of their tube models a try.

I ordered a Lite Audio DAC 60 Modified by Pacific Valve from the Pacific Valve & Electric Company, along with a pair of Jan Phillips 6922 tubes to try out. In this unit they upgrade some of the internal components, as well as make some circuit changes. It would be interesting to compare it to a stock DAC 60 unit to see what the circuit changes are. I will check to see if anything else can be easily tweaked, it looks like it should be very easy to mod.

I'll let you know how it all turns out.

I guess my car parts will have to wait a few more months

Mike

[inertial]

Hi Mike,

I have do not understood completely your statement.
Do you have just ordered the DAC60? When ?Is it a coincidence?
Or do you have the DAC in your hand today?

I think Pacific Valve have made some modifications in the PSU and upgraded some caps, etc. Not sure if they have also modified the point of work of the ECC88 SRPP.

IMHO, if the DAC has a standard 2V output levels, you can connect direct to the power amp by a 20K pot. ( threshold has 75K input and it is enough sensible).
As Nelson Pass says " less is better" ( I hope the citation is correct )

Always if you do not have to connect a turntable also !

Cheers,
Paolo

[msb64]

Hi Paolo

After you had told me about the Lite DACs, I then went and did some checking on the internet and found them at the Pacific Valves website. I had never heard of them before.
I found some independent reviews online that said many good things about them too.
The price was reasonable as you had stated, so I thought I would give one a try.
I just ordered the unit yesterday, I should have it in about a week or so.
I ordered this model http://www.pacificvalve.us/LTDAC60M.html and also ordered the Jan Phillips tubes to go with it, as the supplied Sovek tubes are not rated very well.
I am aware that most cd players, dacs etc have fairly high outputs that are capable of directly driving an amplifier, and a simple volume control can be made up to connect the two.
I have heard in some cases this may not give the best sound, as the preamp can act as a buffer between the 2 devices. Direct coupling of the 2 may cause some undesirable results. In any case a simple volume control is easy to make and try, and I will try it for sure.
I want to try some component changes myself later on too, when my parts arrive.
I will let you know how it turns out. thanks again!

Mike

[inertial]

WOW!
Mike I am embarassed
You have follow only my word. I am extremly glad of this

I think you have a real bargain with the Lite60.
I am very interested also in that DAC so I want ask you a favour:
Can you ask to Pacific Valve the electrical schematic of the analog output stage? ( even also the digital would be appreciate )
Because chinese-sellers are not disponible to give me the wiring diagram, even if I purchase the DAC!

About passive Vs active preamp I think magazines have big/bad contribute on this point.
They have to "inform" the readers , not think only to make happy
preamp's factoryes
In your specyfical case you are lucky: The Zout of the DAC is "low"
( about 1K- and capable of discrete current) and the Zin of the Threshold is high ( 75K, thanks Nelson!).
If you take signal cable short ( after the pot) you can go direct
without any problem
Take a good pot for try, not over 20K , and listen yourself.

Excerpt I do not know Zin of the Hafler, this can be a problem.
Another reason to have tubes amps is they have HIGH Zin .....
You have to check also the Beta's electronic crossover.
I believe to remember the high pass is symply "duplicate"- No filter nor buffer here- . The low pass has his buffer.
You have to check the exact values on the manuals to be sure
the passive can work without issues.



Cheers,
Paolo