L75 tonearm - repair or replace?

[smiorgan]

Hi, I have a GL75 with what appears to be the stock tonearm.  I'd like opinions on whether I should refurbish or just replace the whole thing - looks like the stylus and the arm itself are dodgy, and the tonearm cable leaves something to be desired.
- the stylus looks like it's bent more sharply down than I would expect (say 60 deg from the base of the cartridge).  Is this normal?
- the tonearm has a lot of play at its base, and the counterweight seems to droop.  Also the tonearm can be rocked around its axis when holding the armtube
- the needle does not sit in the groove.  Actually I wonder if the needle is actually contacting the groove, and if it is actually the edge of the stylus.
- on the rare occasions the arm has tracked a record properly the sound is tinny and there is a lot of noise.

Possibly I need to change the downward pressure according to the manual - but all of this sounds like I might be better off getting a new tonearm and cartridge rather than trying to refurbish this one and spending a lot on small repairs.  Are there any cheap fixes I should consider?

Thanks
Ralph

[ropie]

Hi Ralph and welcome,

the tonearm cable leaves something to be desired.

These can be quite easily replaced if you can use a soldering iron.

the stylus looks like it's bent more sharply down than I would expect (say 60 deg from the base of the cartridge).  Is this normal?

A photo would help here but it sounds like it could be bent.  Depending on the make of the cartridge it's not usually difficult to replace the stylus - what make is the cartridge?

the tonearm has a lot of play at its base

I think this is normal and is due to its construction, but don't quote me..

the counterweight seems to droop

This is a common fault of these arms once they get to a certain age.  It is fixable but can be a bit fiddly.  There is probably some info somewhere here about remedying this - anyone know where?

Also the tonearm can be rocked around its axis when holding the armtube

Again, I think this is down to how it's constructed (?)

- the needle does not sit in the groove.  Actually I wonder if the needle is actually contacting the groove, and if it is actually the edge of the stylus.
- on the rare occasions the arm has tracked a record properly the sound is tinny and there is a lot of noise.

Either you need a new stylus or, as you say, you need to adjust the downforce.  As it is an old table I would personally be inclined to get a new stylus anyway and possibly a whole new cartridge.  One other thing - did you use a phono amp or the phono-input of the amp when testing the arm?  If not you would not hear much more than some tinny scraping.

It shouldn't cost you too much to refurbish this arm (new cables, new v-blocks, soldering iron if you don't have one (always useful!) - c.£50 total).  Lots of people like these old arms as they are original and can be made to sound quite good, but I have never really used one.  There are many options for a replacement arm but that's another post..

[smiorgan]

A photo would help here but it sounds like it could be bent.  Depending on the make of the cartridge it's not usually difficult to replace the stylus - what make is the cartridge?

Shure.  Don't know the model number, I will have a look and take a photo if I can

One other thing - did you use a phono amp or the phono-input of the amp when testing the arm?  If not you would not hear much more than some tinny scraping.

Hah!  Yes, I did use the correct inputs - this isn't my first turntable.  But doesn't hurt to state the obvious

Cheers
Ralph

[flavio81]

Smiorgan, first let me point out that you have described problems with three different components:

- The phono leads that come out of the turntable (cables that connect from the TT to your amplifier)
- The cartridge and the stylus
- The tonearm itself.

Since you can replace the cartridge, and you can replace the phono cable and leads, and information about those is ubiquitous in the web, let's discuss about the tonearm itself only.

Before you continue reading this, you must first have a look at the exploded view of the tonearm here:
http://www.lencoheaven.net/forum/index.php?topic=69.0

I'd like opinions on whether I should refurbish or just replace the whole thing

Refurbish, even if you get another tonearm, the stock tonearm is good as a 2nd tonearm for 78rpm or mono.

- the tonearm has a lot of play at its base,

Tighten the screws that adjust tonearm height. Then fix the rest of the things detailed below. If there is still play at the base of the tonearm (the base should only rotate horizontally, with no vertical play), then you need to tighten the horizontal bearing, which is done using the nut below the tonearm pillar. Items #6 and #4 on the tonearm pillar image.



Again, you should not need to adjust items 6 and 4, unless the vertical play is still there. Adjusting them takes time: Adjust it for the lowest friction possible while mantaining no vertical play.

Also the tonearm can be rocked around its axis when holding the armtube

This is normal, because the vertical bearing is a knife-edge bearing. Still, you MUST replace the part of the bearing known as "v-blocks". These go inside item #10 of the diagram. Replacing them is very easy. Check out this thread:

http://www.lencoheaven.net/forum/index.php?topic=2009.45

If you still don't know where the v-blocks go, look at this pic. This guy has replaced it's v-blocks with little blue plastic pieces (not the best idea, but the pic is useful)

and the counterweight seems to droop.  

This is a normal problem, the accepted solution is to make the two-part tonearm rigid again by filling the gap between the two tonearm tubes with dental floss and applying glue:

I might be better off getting a new tonearm and cartridge rather than trying to refurbish this one and spending a lot on small repairs.  Are there any cheap fixes I should consider?

Reparing that tonearm is very cheap. I did it using only household items. A repaired tonearm decently good, in my opinion, and it was an excellent tonearm for 1969 standards.

[flavio81]

Related thread on v-blocks:

http://www.lencoheaven.net/forum/index.php?topic=2009.45

[skippingjack]

It might be because I'm in the middle of a rewiring/refurbing of an l75 tonearm at the moment that's going really badly, but if I was going to give you any advice it would be to take the arm of, pretend it never existed and fit something else.

A mission 775lc tonearm or linn basik can be picked up quite cheap and are a lot less hassle.

Alex

[rleon]

How do you rewire the tonearm without destroying it?

[skippingjack]

I didn't manage to rewire the arm without destroying it, I had to cannicalise another to get the connector out, see http://www.lencoheaven.net/forum/index.php?topic=3946.0

However, hacking it up gave me better knowledge of how the connector fits in. I think it is possible to remove the headshell connector with out destroying the arm if the pin holding the connector in place can be removed. I would trying teasing the pin out slowly with some pliers, fit a headshell to the arm and then twist the headshell in the mounting to screw the connector out.

Alex

[colin]

Hi Ralph,  welcome to LH.

Your 75 is typical of the breed, your arm is tired.  First things first -

the arm is supposed to pivot up and down on some v shaped bits of rubber called v-blocks.  When the v-blocks wear down the arm actually pivots on the chrome shroud before the needle hits the groove - watch your arm tube closely as you lower the arm.  The quick answer?  - put 3 records on the platter and play the top one,        - you have raised the playing surface back into range of the tired v-blocks and stopped it pivoting on the shroud.

The Shure cartridge is probably a 44 or 55 and the cantilever does look different, so it might be ok.  If it's the 55 then you have the best cartridge for this arm imo, keep it.

Hth