Goldring-Lenco GL78 speed issue

[Steveatbath]

i recently played some 78rpm discs on this variable speed deck and checked the running speed with the stroboscope which came with the deck. This showed that the speed at the detent was slightly fast, actually 80rpm, confirmed with another specific strobe. Checking at 33 and 45 rpm also showed a similar excess. I also use a belt drive Thorens TD150 at 33rpm and the strobe again showed a similar excess ie about 2%. Can anyone offer an explanation? I assume that the pitch difference for any recording would be slight but possibly significant.

[Nickthedentist]

Note that the detents are adjustable. Just slacken the adjacent screw.

[Uncle Bulgaria]

The settings are for you to adjust. The speed selection lever is infinitely variable, and the notches/cradles it falls into are user-adjustable. You can play records at any speed between the limits of the lever's slot. Simply loosen the screw on the relevant speed notch and move the cradle. Use your stroboscope to ensure it's correct, then tighten the screw. This can be very helpful if you have a deck set up for early '78s' as the speed varied dramatically between different record labels, before 78rpm became standardised.

[Julesomega]

Early '78s' sometimes show the pitch of the performances so you could tune the playback speed agains a piano
https://www.45worlds.com/i/1b699a1308ab8490e6f

[lazythread]

If both your turntables are affected then it could be your mains voltage is high. Ours is usually around 250-252 volts. Incandescent light bulbs burned very brightly and never lasted very long. I understood that the tolerance allowed back then was +10% of 230 so there was little we could do.
I just moved the four detents on my Goldring G88 to compensate.
I know that synchronous motors depend on mains frequency for speed accuracy, otherwise you are at the mercy of your mains voltage.

[Steveatbath]

Thanks for the replies and I will continue to check and make adjustments. I think I have a Dual 505 deck somewhere with adjustable speeds so must look at that.

[Uncle Bulgaria]

I misread your initial post, thinking you were saying your GL78 was not the same speed as your Thorens. Does your motor have the screw to adjust the voltage? On many Lenco motors there are options for three or four mains voltages. However, I think the highest is 225V, with the normal 220V. Since it's an induction rather than synchronous motor, if your mains voltage is higher then even at the highest setting the motor will run a little fast. It shouldn't be as much as you've measured, but it would have an effect. It can be cancelled with the detent adjustment as already described, but your Thorens will still be out of inaccurate by comparison.

[Michael Maurice]

I use an app on my phone called RPM, I use it because the new lighting does not work at 50Hz

[Michael Maurice]

Originally Posted by lazythread

If both your turntables are affected then it could be your mains voltage is high. Ours is usually around 250-252 volts. Incandescent light bulbs burned very brightly and never lasted very long. I understood that the tolerance allowed back then was +10% of 230 so there was little we could do.
I just moved the four detents on my Goldring G88 to compensate.
I know that synchronous motors depend on mains frequency for speed accuracy, otherwise you are at the mercy of your mains voltage.

It has nothing to do with mains voltage, the motors are frequency dependant which should be a constant 50Hz

[Uncle Bulgaria]

Lenco Heaven claim the Lenco motors are four-pole induction, not synchronous. They advertise a 0.2% speed change per 10% change in supply voltage.

[Nickthedentist]

… whereas the Thorens is genuinely a synchronous motor.


Dad had one when we were growing up and I can remember trying to play along with it on the piano and cello and finding it about half a semitone sharp.

[Steveatbath]

It’s good to read the responses and I can report that I have reset the detects on the GL to match the strobe ratings. Some of the small screws were very stuck and had to be eased with WD40 and graphite oil. It was difficult to find an old bulb and holder to shine on the strobe; can Moderator Michael say more about the RPM app? I read that Nick had a similar experience with the slightly fast Thorens. My TD150 has been spinning happily and steadily (albeit fast) for over 40 years with perhaps 2 new belts but no other attention. Somewhere I have an older TD35 which I think is disc driven and may have speed adjustment; I’ve not looked for years! Time to search and hope it still works!

[Steveatbath]

I have now been playing 78 discs (after cleaning) at the correct speed on the GL78 and enjoying the specific experience of the single side span, the remarkable quality from such old artefacts, and some fascinating printed sleeves, many advertising music shops in various cities. Some early disc labels state a speed of 80 rpm but one recorded in 1915 has no speed indicated. This may be a special disc given the number, L1001; is it perhaps the first issued by the Columbia Graphophone Company? Beecham conducting the Magic Flute Overture.

[Uncle Bulgaria]

This discussion on Discogs includes a snippet from a 1922 Columbia (UK) catalogue that states all Columbia records should be played at 80rpm.

What cartridge/stylus combination are you using for your shellacs?

[Gabe001]

Originally Posted by Steveatbath

It’s good to read the responses and I can report that I have reset the detects on the GL to match the strobe ratings. Some of the small screws were very stuck and had to be eased with WD40 and graphite oil. It was difficult to find an old bulb and holder to shine on the strobe; can Moderator Michael say more about the RPM app? I read that Nick had a similar experience with the slightly fast Thorens. My TD150 has been spinning happily and steadily (albeit fast) for over 40 years with perhaps 2 new belts but no other attention. Somewhere I have an older TD35 which I think is disc driven and may have speed adjustment; I’ve not looked for years! Time to search and hope it still works!

The screenshot attached shows a widely used rpm app. Just be aware that mains frequency varies by 1%, and so will your rpm measurement using the app, whereas a mains powered strobe will show a constant value. If your wow value is high, make sure your TT is flat and level and try again. The GL78 is capable of keeping a nice constant speed when set up correctly.

I never had a thorens but I did have a pl12d and the aftermarket belts make a difference to the speed. They're not all the same. Took me 3 belts to get it to 33.8rpm which is the best I could do.

You may know this already, but there is a very good Lenco group on Facebook with some extremely knowledgeable people some of whom sell upgrade parts. Don't go crazy, but the tonearm upgrade may be worth considering, especially if yours sags at the back (common issue) .

[Uncle Bulgaria]

Lenco Heaven is another website dedicated to these. Here's a way to rebuild a sagging tonearm while retaining the resilient counterweight mounting.

[Edward Huggins]

Originally Posted by Steveatbath

I have now been playing 78 discs (after cleaning) at the correct speed on the GL78 and enjoying the specific experience of the single side span, the remarkable quality from such old artefacts

I have some Pye Nixa Vinyl 78s. They have a great attack, surprisingly good treble and low surface noise. I think much of this is to do with the sheer velocity and driving force onto the cartridge.