Exhibition peaking in high mid area

[scullylathe]

OK after reading the thread on the Victrola #2 I figured I'd get industrious and tweek the Exhibition on my Victor VI. It had been sort of 'dead' sounding which I was attributing to the gaskets. Forgot that I replaced those when I bought the machine years ago. OK, so after a complete disassemble, cleaning and reassembly I noticed that the springs only held the stylus chuck arm where it needs to be with the adjusting screws tightened all the way. I figured I might be able to bend them to provide a little more of a spring action, but I noticed that they seemed way too easy to bend, as well as hold the new shape without any 'spring'. I've been collecting, repairing, etc. for over 20 years and it seems to me that the springs for these were supposed to be stiffer, possibly even made from actual spring steel and not just a regular piece of stamped metal. After putting everything back together the sound is much better, but now it peaks in the mid/high-mid area almost to the point of being obnoxious. I've tried all the 'tweeks' I've been taught over the years but can't seem to get the nice even range of a properly adjusted mechanical reproducer. I serviced the Exhibition on a Victrola VI years ago and I seem to recall the new springs had a bluish tinge like they were spring steel. Anyone have any insight as to what's happening?

[Henry]

Have you checked the needle-arm-to-diaphragm spacing? Victor directions say that the needle arm should just barely make contact with the diaphragm; this spacing is varied by adjusting the nuts holding the springs (one side increases, the other decreases, the distance, I forget which). When I rebuilt my Ex, I used a piece of cigarette paper as a "gauge"; when I could *just* feel drag on the paper when I withdrew it from between the needle arm tip and the diaphragm, that's where I left it. Final step: seal with beeswax. Seems to me that if everything else is in order (new soft compliant front gaskets, good new back flange with proper air seal, diaphragm in good shape, etc.) your Ex should sound as good as mine does, which is very good indeed. See also http://www.nipperhead.com/old/rep_exhib.htm for reference.

P.S. Don't take up smoking to get the cigarette paper! Buy a packet of it at the drugstore or tobacconist

[scullylathe]

Thanks. I didn't think of using beeswax which would be a little softer for the center screw seal. Leo Hirtz taught me years ago to "use a little piece of a broken wax Amberol - we all have one!" I miss Leo.

OK, maybe I shouldn't have tried setting it with a slight 'backlash' as suggested for the Vic #2. It wasn't much, but it may affect the sound quality dramatically. I've never been told to set any disc reproducer with a slight outward 'pull' as suggested in the thread on the #2 and usually do exactly what you recommend. I'm still wondering about the springs. The new ones I bought (I think from George Vollema) several years ago for the Exhibition I repaired for a Victrola VI had a slight bluish tinge to them which made me think they were spring steel. These are original to the reproducer, but look like plain iron or steel and bend fairly easily. Leo also recommended making tiny kraft paper 'washers' for the front and back side of the diaphragm where the screw goes, putting them in place, tightening the screw, then applying the wax seal. According to Leo, the original reproducers had the tiny paper washers. Will re-set the arm and try the beeswax.

[Henry]

Yes, there was a tiny paper washer involved with the needle-arm-to-diaphragm contact, but I omitted this in my rebuild. I'm not sure that the washer had a direct acoustic function; I suspect that it was there to control or limit the wax flow. Speaking of wax flow: applied to the front of the diaphragm face at point of needle arm contact, wax will flow through the screw hole onto the back face of the diaphragm. This is not a bad thing! The goal is two-fold: to prevent air leak at that point of penetration, and to distribute the sound vibrations over the diaphragm face, while damping out the excessive vibration which causes distortion. At least, that's my theory!

As for the springs, those on my Ex have not been replaced AFAIK. I believe their function is to impart some torque or bias to the adjustment of the fulcrum-and-lever arrangement at the base of the needle arm. I'm not sure what part, if any, they play in the acoustical aspects of the sound box.

In re: beeswax. There was a discussion, maybe on OTVMMB, about the different kinds of wax, where it came from in the hive, etc. One of the posters, also a beekeeper, recommended the brown wax over the yellow, for reasons which are now vague in my memory. In any event, I happened to have some of the brown, so that's what I used.

[scullylathe]

Well, I got busy last weekend and replaced the diaphragm gaskets with new material and used paper washers and beeswax to seal the needle arm - it sounded a little better but still not as it should. Took it off the machine again and was looking at it and noticed light between the back flange and the reproducer. Hmmm - air leak. I'd had the back flange rebuilt about 8 - 10 years ago (I don't recall who was offering the service at the time) and the rubber material used had shrunk terribly over time, leaving gaps. Used some caulk to temporarily seal the reproducer until I can get another flange and now the sound is closer to what it should be. I did notice that the diaphragm gasket material I bought a few years ago is larger and not as pliable as the original gasket tubing. It's pinching the diaphragm so tight I'm thinking this is affecting the tone quality now. Does anyone happen to know if the material from APSCO is the original soft white latex rubber or the vinyl-like stuff that's been sold in recent years that's just too hard for this purpose? I recall at the time I bought the new material, the original wasn't available anywhere.

[Amberola 1-A]

I buy my tubing from Ron Sitko. He supplies the correct soft tubing and not that other material that I agree is too hard. Here is his contact info:

Ron Sitko
56 Church Hill Road
Waterford, NY 12188
518-371-8549

He does not have a web site and it's best to call in the evening. He also carries other phonograph replacement parts such as flanges, springs, belt material, etc.

Bill

[Henry]

Another source for the good pliable white gasket material is Victor Repair Service (see http://www.victrolarepairservice.com/parts.html ). They rebuilt my Exh. using this very compliant material, and it has made a huge difference!

[scullylathe]

Thanks for the leads - I'll get in touch with Ron. I remember his name from my dealings with Leo Hirtz. (Almost 30 years ago!!!!) There also was a guy in MN somewhere, Jerry something that Leo referred me to years ago. I've since lost his contact information. Sort of been out of touch for years and need to get back in the swing of things. (Or foxtrot )

[JohnM]

Probably Jerry Madsen in Edina, Minn., but I think Jerry isn't very active anymore.

[scullylathe]

That's right - couldn't remember his last name.