Sounds like an interesting mod Quiltzig, did you happen to take any pictures of it?
I haven't even peeked inside my own servo box yet myself.
The same goes for my Threshold S10 preamp, I probably should look into replacing the old electrolytics in them.
Hi Paolo
I would definitely be interested in hearing about what you recommend for upgrading the crossover in the mid high towers.
I still haven't attempted upgrading the coils yet, their increased physical size would require some good planning to mount them safely and securely, possibly involving another support platform that would still fit into the base.
Btw, I used to have a pair of Deltas myself back in the late 80s, and am still kicking myself for not hanging on to them.
I have been working on modifying my car for the last 4 years, but have time again to work on audio gear.
With the down to -40C winters here, working on audio gear makes for a nice indoor activity.
Mike
Hi Quiltzig
Just a reminder, if you are going by the Beta schematic for the crossover when ordering upgrade components, keep in mind that there are at least 2 errors on it.
The C10 value on the midrange should be 50 mfd (Solen), not 500 mfd.
The C16 value on the midrange should be 10 mfd (Wondercap), not 100 mfd.
The Wondercaps are fine, so you shouldn't have to worry about C16 in any case.
I haven't come across any other errors yet, but the rest of the values for the NP cap values are correct according to my actual oem crossovers.
Some of the values can be difficult to read, as there may be other bypass caps hot-melt glued right over the big cap markings.
Mike
Btw, the servo schematic indicates these electrolytics which are probably overdue for replacement
C12 - 100 mfd 15 volts (1 - right, 1 - left)
C13 - 10 mfd 16 volts (1 - right, 1 - left)
C25, C28 - 2200 mfd 35 volts x 2 (not sure if it is 2 or 4 total)
C29 - 10 mfd 50 volts
C12 - 100 mfd 15 volts (1 - right, 1 - left)
C13 - 10 mfd 16 volts (1 - right, 1 - left)
C25, C28 - 2200 mfd 35 volts x 2 (not sure if it is 2 or 4 total)
C29 - 10 mfd 50 volts
HI,
icreased quality of original crossover is not a good idea because betas already emplyoed very good components 🙄
i' was referring to take a set of measurements mls of the raw drivers ,
to say at 2- 2, 5 mt, and acquisite datas to input in x-over prg modeler.
cheers
Hi all, New diy member to an old post. My Beta's have a buzz in one woofer tower that needs repair and am considering all options as discussed here… replacing electrolytics, and possibly other caps and wire. Would be interested in follow-up comments by msb64 and others concerning how their upgrades sound, things they would have done differently, or wish they would have done. Any recommendations of capacitors brands that you would recommend to use (no changes to the schematic) and their sonic signature. Plus if you have any ideas about the cause of the buzz, I'd love your input. It seems to be in the Servo box… not the speaker itself. Switching towers right to left the buzz stays in the same side, switching amp and preamp leads, and leads to the Servo box all point to the problem in the Servo box. Any thoughts?
Thanks in advance. This has been a great thread.
Thanks in advance. This has been a great thread.
Hello Folks. New here and I was wondering as I own a set of the Betas and the question is my amp for the bass towers (Krell Fpb400cx) does not have single ended inputs I am using Xlr to rca adapters, Is this the best way to connect the servo unit to the amp or would some sort of transformer be better? thanks for any help
Hi MSB,
Before doing that much effort, it's really worth analyzing the speaker from top to bottom, and simulating the crossover. I've seen many an old speaker be designed with really odd things, including deliberate impedance drops for the sake of appearing more "discerning" or more sensitive. I've seen some evidence online of really wonky crossovers coming from Infinity before. Some of these wonky crossovers may have been a result of not having the tools we have now, and just trying to fix a problem through repeated experimentation. In either event, it's worth looking at the whole design, stepping back and rethinking it first.
Having said that, Mundorf MKP are my top recommendations for high pass caps. I second Mills. Be careful with replacing big iron coils. The low DCR may be part of the design, so it's really worth while to simulate the design first and compare any proposed coil changes.
Best,
Erik
Before doing that much effort, it's really worth analyzing the speaker from top to bottom, and simulating the crossover. I've seen many an old speaker be designed with really odd things, including deliberate impedance drops for the sake of appearing more "discerning" or more sensitive. I've seen some evidence online of really wonky crossovers coming from Infinity before. Some of these wonky crossovers may have been a result of not having the tools we have now, and just trying to fix a problem through repeated experimentation. In either event, it's worth looking at the whole design, stepping back and rethinking it first.
Having said that, Mundorf MKP are my top recommendations for high pass caps. I second Mills. Be careful with replacing big iron coils. The low DCR may be part of the design, so it's really worth while to simulate the design first and compare any proposed coil changes.
Best,
Erik
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