R85 Starlight - amp component question

[tinkerguy]

Hello everyone !!   I am now adding Jukeboxes to my  tinkering list....

I am working on an R85 starlight for my FIL, and I'm working on recapping the amps right now.  6-07438-94 amp, preamp board has PN 6-08552-01

My main question... as I took out the preamp, there are 2 small lamps either side of the Volume Control connector, DS1 & DS2 on the silk screeen.

One fell off the moment I touched it, the other seems to be in pretty poor shape as well.

Do either of these bulbs serve any real purpose?  I know some neon bulbs are used as triggers... 

Should I...

1) ignore them and just finish the recap.
2) replace them with proper parts?  (which are?)
3) replace with LED?
4) just jumper the connection?

Second question...

I plan on replacing the thin film caps as well as the electrolytes.   What is the units on the thin films?   They have the ratings, but not the units (uF, pF).  

And lastly, since I'm here, any other things I should consider doing while I have the amp on my workbench?

Thanks in advance for the tips...

Oh, and just since this is my first post..  I tinker with pachinko machines, 3D printers, slot machines, pinball, and most anything else I can get my hands on that I find interesting.

[Ron Rich]

Hi Tinker-er--
One-- please read the PM you were sent.
2. Do you have the parts catalog for your phono-- funny, but I think the parts list, and schematic may just be there?
The mini lamps are used in the volume control circuit-- no, you can not "jump" them-- You may use either the correct lamp numbers , or substitute 2 # 2182 , or #73's, for each one-- wired in series. I suggest you use some "bathtub rubber sealer', on the lamps, to attach the glass to the board.
I also do not understand your use of the term "thin film caps"-- All cap values should show in the schematic, and/or, parts lists ? Ron Rich

[tinkerguy]

The manual I have does not have the parts list nor the schematic, which is why I came here to ask for help.

Therefore, I also cannot read the schematic to get the correct values, I'm reading them off the parts themselves. And the parts used on this board have the numerical value but do not have the units printed on them. I can attach a pic if you like.

And as far as thin film capacitors...

en.wikipedia.org/wiki/Film_capacitor

[Ron Rich]

On the service manual-- this is why you were requested to read the Hi Newbies post--which tells you to purchase a "good" Service manual, SET ! What do the caps say on them, that you are questioning ?
On the "film" caps-- IF you are 100 % sure they are really "film", not plastic covered paper caps -- they should be OK. Ron Rich

[tinkerguy]

wow.... have fun in your elitist little world, here's the award for being the most unfriendly hobby board I've had the displeasure to join.

[Ron Rich]

What didju expect ? I own over 300 service manuals--but not that one-- I axked what it said on the caps--was willing to try to ID them for you-- but I just don't have that manual to read to you ? You can't even bother to sign your name, or note your location, as requested-- talk about "elitist"----Go else ware to "tinker"--please !
Please Ron Rich

[tinkerguy]

And just to leave a solution here for those who may be seeking an answer.....

I found this (really) old post out in an archive.....

"Customers with a Rowe R-85 juke (and probably R-84 and R-86 and maybe later models):- The circuit for the pre-amplifier in the 125 watt stereo amplifier model (amplifier assembly complete is part # 6-07438-02), shows DS 1 and DS 2 as current limiting lamps (GE # 1764, Rowe part # 2-15458-01 or F 15458 A) in the volume control circuit. It is most likely that these lamps are not fitted; it appears that during the production run, Rowe changed their minds and replaced these lamps with 270 ohm ¼ watt resistors. The # 1764 lamp is very obscure these days and not easy to find either! It is a wire-terminated lamp 28 volt, 40 ma ( = 0.04 amps)."

Based off the specs listed here, I was able to find the following bulb on mouser. com


www.mouser.com/ProductDetail/560-7327



I chose not to go with the resistors, as in different references on my way to finding the post that claimed the resistors sounded "muddy" compared to the bulbs.



And as far as the film capacitors, the stock ones are rated at +/- 10% tolerance. I am replacing them with ones rated at +/- 5% or better, this is a standard practice used to improve sound quality on audio amps (although there is debate about how effective it is)

[Ron Rich]

Thanks for that info-- I gave you two lamp subs, in my first post-- ?? Ron Rich