JVC/ Nivico SRP-471E-3

[Wolfie62]

I made wax molds of the motor mount bushings. Then molded black RTV silicone bushings. Works well! Clear RTV is also good.

 

[woodturner]

I found a few soft silicone mounts for a CD transport that worked well for the motor mounts, and then cut some thick neoprene for the assembly mount. It "feels" like it might work OK, but it will be another few hours work to finish and connect it up. So I won't know for sure for a bit.

 

[olaf_from_SA]

Most of the idler wheels I've seen are like a hard rubber. The bigger wheel here is like, squishy. Any vibration that makes it to that thing will be dead in a hurry.

which speed setting is the table on when the intermediate idler is right at the top of the motor pulley?

 

[olaf_from_SA]

I've uploaded some pics here from the underside of mine before I started to strip it down. Hopefully it helps find where that spring goes.

Mine too has the disintegrating foam motor mount bushes. One or two though were still fairly OK, so I managed to get some measurements from them. I'll post them next. I think the only hope here is to make something else work, maybe an RC car rubber mount or something.

Thanks for the photos. Please share some more while stripping the table down. Couldn’t see where that spring goes if anywhere just yet.

Here’s a picture of the smaller motor mount. I’ll post a sketch with dimensions as well.

 

[olaf_from_SA]

I made wax molds of the motor mount bushings. Then molded black RTV silicone bushings. Works well! Clear RTV is also good.

I’ll give this a shot!

 

[woodturner]

I'll take a few pics in the morning, I got a lot done with it today.

The deck I have looks identical to the ones here but the number on the sticker says model SRP 93 CL. It has a 0.9uf cap (measured at 0.82uf, reasonable esr, so I left it in place). The pulley set up is interesting. The deck can be set up for 230v or 110v operation, with a transformer to step it down to 100v. The motor is synchronous, so it will run at either 50hz or 60hz. The pulley is spring loaded, with 4 steps, you just mount it higher or lower on the shaft for 50 or 60hz operation. Very clever I have to say.

The bearing isn't just the best one ever, seems to be oilite type as far as I can see with a ball at the bottom of the well. Many of the pivot points were gummy in mine, so I pretty much disassembled every one, cleaned and regreased all of them. They should last many years with modern greases.

I gave the idlers a good clean, they are both supple and feel in good condition. Table runs very freely now.

The arm was a **** show. The pivot points had worked loose and whatever bearing cups were meant to be in there were long gone. I made some new ones from brass, it "feels" ok. On some testing, the grounds were wired together at the headshell mount. I ended up rewiring the arm completely with some copper litz. I replaced the old RCA leads with new ones, and the same with the power cord. I just need to arrange the grounds now and all should be good.

Last up I gave it all a good clean, the chassis is drying off overnight. I'll give it a coat of wax tomorrow and that should protect it. The chassis is only ok on this one, there are a few nicks in it.

Hopefully I'll do a final assembly tomorrow and I'll post the pics.

 

[woodturner]

So attached is a pic showing where that spring connects - it's under the chassis, connects to a post that's moulded into the chassis. You'll see how in the photo we are looking in from the side and you can see the eddy plate on the motor in the background. It's sort of hidden between the motor mount and the chassis.

Second photo - where should the antiskate connect to the arm - red arrow or green arrow?

 

[olaf_from_SA]

So attached is a pic showing where that spring connects - it's under the chassis, connects to a post that's moulded into the chassis. You'll see how in the photo we are looking in from the side and you can see the eddy plate on the motor in the background. It's sort of hidden between the motor mount and the chassis.

Second photo - where should the antiskate connect to the arm - red arrow or green arrow?

that answers my question exactly! Thanks a lot. Attaching a picture of my table. Doesn’t have that little post, only a hole where it’s supposed to be.

I’m pretty sure it’s the Green Arrow.

 

[woodturner]

Thanks!!

So I have it all back together now, looking a lot better than it did!!

It runs and holds speed fine, I got the auto return working pretty OK - although its still not perfect. Good enough to go listening at least. The original stylus was toast, so I fitted an old ortonfon FF15 on it to get it going. But here I have hit a problem. I have a lot of hum/buzz, undoubtedly related to grounding. I did replace the tonearm wiring as it had broken and was gone very stiff but I don't think that's it. Has anyone had this issue before? The grounding scheme at present (which mirrors the original):

Arm ground connected to left hand cart ground
link wire from left hand ground to centre post of tag which is tied to the deck chassis
Motor linked to subchassis, linked to the centre post
No conventional mains safety earth, essentially a 2 conductor cable back to mains supply.

I've done a few small bits of tricking about with it, but no solution yet.

Any ideas welcome!


fran

 

[olaf_from_SA]

Here's a drawing of the smaller rubber bushing... 52992-1 Rubber Bushing

 

[woodturner]

Can I ask another question on this deck. Should the motor be tightened right against the chassis sub plate? I take it these should be "loose" a little so that there is some damping between the motor mounting and the rest of the chassis?

 

[jobrewer1983]

Just bought one of these completely refurbed. Double idler drive with auto-return, and you can turn it to manual. Has a pitch trimmer and its from 1966. Must be a flagship table from these guys. Talking to the seller, he says this table is one of the best he's ever heard. Im excited to hear it myself. Its on its way in the mail now. Good thing is this guy knows how to ship a table without damage. Any fans of this beautiful table?

I have one of the arms, and a headshell. I use the headshell on a custom PL-41. Haven’t mounted the arm to anything. The head shell is beautiful and hard to find. Really nice table ya got!

 

[woodturner]

Just to update the thread. Twisting the tonearm wires helped a little, but using a shielded cable to the RCA jacks cured the RF/hum pickup issues.

 

[olaf_from_SA]

Can I ask another question on this deck. Should the motor be tightened right against the chassis sub plate? I take it these should be "loose" a little so that there is some damping between the motor mounting and the rest of the chassis?

I don’t think it should be all the way to the top.

If mine is too high the middle idler isn’t ‘seated’ on the motor pulley correctly and it ends up turning too fast.

 

[samrobertson]

Lots of good stuff in this thread and it looks like a mention or two of a problem that’s been driving me nuts. The table usually turns on quietly but quickly starts to emit a terrible wheezing, whirring like noise from the motor area. I lubricated according to the manual (have not taken apart motor yet) but that only seemed to make things worse if anything. Upon inspecting, it looks like the problem is contact between the motor plate and pitch control magnet brushing together. Does anyone have a fix?

 

[olaf_from_SA]

I had that same problem with the magnet scratching the wheel - I bent the angled bracket which the magnet sticks to open to make sure it is square. Solved the problem for me.

 

[samrobertson]

I had that same problem with the magnet scratching the wheel - I bent the angled bracket which the magnet sticks to open to make sure it is square. Solved the problem for me.

I messed around with the table a bunch more this weekend and by and large, that’s not my issue (though there is occasional rattling from there).

I’m having a lot of trouble tracing the noise I have… I’ve lubricated the motor, tightened screws, the motor mounts and idlers look pretty good… yet an unbearable whirring screeching like noise almost every time the platter turns. It seems to maybe be the motor rubbing up against the bracket that holds it from the bottom but I’m really struggling to figure this one out. And it’s driving me nuts because this one did sound pretty spectacular for the couple of days it worked well.

 

[moondogtn]

I no longer have my table but I had that issue. It was the motor mounts. There is one that takes most of the weight if I remember correctly and it sags enough to allow contact. Maybe you have a different issue?

 

[samrobertson]

I no longer have my table but I had that issue. It was the motor mounts. There is one that takes most of the weight if I remember correctly and it sags enough to allow contact. Maybe you have a different issue?

I’m gonna dig back into this one tonight. Did replacing the motor mounts fix it for you and if so remember what was used?

 

[moondogtn]

I had two of these tables so was able to use some of the original softer mounts. The hard rubber from McMaster caused me to have a lot of rumble.
I think someone was developing some mounts specifically for this table. I think someone recently posted up in this thread. If not, you could experiment with generic phono mounts.