Dynatron GR14 Cordova stereo problem. - UK Vintage Radio Repair and Restoration Discussion Forum

ramon56 · 9th Sep 2018, 3:45 pm

Hope someone can help. I've got a Dynatron Cordova mono record player in really nice condition. However, when playing stereo records one channel is barely audible. I know this deck originally came with an optional extra speaker for stereo sound so I tried plugging in additional speaker but still you can barely hear one of the channels.
Could this be just a stylus issue, or something more serious?
Thanks

Edward Huggins · 9th Sep 2018, 5:45 pm

There's no point in plugging a speaker into the "stereo" socket on your Dynatron. You'll not get stereo, in fact you won't hear anything. This socket is for connecting a stereo adaptor unit (i.e. a amplified loudspeaker) for the RH channel. We need to know what kind of cartridge is fitted to your tone arm. It may be a stereo-compatible mono cartridge (2 connectors) in which case you will automatically hear both channels - or - it may be a stereo cartridge (4 connectors) which will need the LH and RH channels bridging. Please advise.

ben · 10th Sep 2018, 8:38 am

These usually came with a Garrard 3000 series deck and a Sonotone 9TAHC or Acos cart, both of which are stereo. If you're missing one channel, check first the connections at the cart rear - be very careful as the wires are very thin and can easily detach from the soldered tags if handled at all roughly.
I do not know if these units have a make/break socket/plug contact for bridging the two channels to mono when not used with extension stereo amp/speaker (a la Bush SRP31) - that would be the next area to check. Perhaps someone here more clued in could advise on this point.

Station X · 10th Sep 2018, 9:25 am

The service data is available here:-

https://www.service-data.com/product...12/1814/a11312

ramon56 · 10th Sep 2018, 8:00 pm

Quote:

Originally Posted by Edward Huggins

There's no point in plugging a speaker into the "stereo" socket on your Dynatron. You'll not get stereo, in fact you won't hear anything. This socket is for connecting a stereo adaptor unit (i.e. a amplified loudspeaker) for the RH channel. We need to know what kind of cartridge is fitted to your tone arm. It may be a stereo-compatible mono cartridge (2 connectors) in which case you will automatically hear both channels - or - it may be a stereo cartridge (4 connectors) which will need the LH and RH channels bridging. Please advise.

Thanks Edward. I've attached a pic of the cartridge, does this tell you anything? I thought maybe the 'S' means stereo?
Actually the 2nd speaker just reproduces the sound from the main speaker - ie very quiet LH channel.

'LIVEWIRE?' · 11th Sep 2018, 8:58 am

You've attached a picture of the stylus not the cartridge. The 'S' does indeed stand for Stereo. This simply means that the stylus tip is of a radius suitable for playing stereo records. The cartridge is the item into which the stylus clips, and will have a make/model no. similar to those suggested by Ben in post # 2, although it could be another make and model.

ben · 11th Sep 2018, 9:02 am

That looks like a BSR ST12/14/15 to me, though I've not seen one with the lettering embossed before. As suggested by LIVEWIRE, a picture of the cartridge in the arm would help. I suspect someone has replaced it at some point in time and not connected it up correctly.

ramon56 · 13th Sep 2018, 7:25 pm

Quote:

Originally Posted by 'LIVEWIRE?'

You've attached a picture of the stylus not the cartridge. The 'S' does indeed stand for Stereo. This simply means that the stylus tip is of a radius suitable for playing stereo records. The cartridge is the item into which the stylus clips, and will have a make/model no. similar to those suggested by Ben in post # 2, although it could be another make and model.

OK here's a couple of pictures of the cartridge. The only identifying features it has are '52T' and 'Japan'. A google search would suggest this is a Sonotone cartridge. the deck is a Garrard 1000.
The cartridge has 4 wires connected, all seem to be firmly soldered and connected properly.
Perhaps I need to remove the deck and investigate the other end as suggested by Ben?

ben · 13th Sep 2018, 11:18 pm

That's a Sonotone 52T. Very scarce outside the US. It may well be knackered like quite a few of this era now are.

One quick test before condemning it. Put the volume about midway. Get a small jewellers metal screwdriver and , with the arm raised as in your first photo, gently touch each of the 4 contacts. On two there should be a loud ish buzz. Post back with findings.

ramon56 · 14th Sep 2018, 4:52 pm

Thanks Ben, I tried that and yes indeed, two of the wires buzz (the green and white if that makes any difference).

John10b · 15th Sep 2018, 9:08 am

Just a thought, you may be able to fix the Cartridge, could I suggest you take a look at some pictures on the thread “bass response....”. I opened a Sonotone cartridge and found corrosion on the pins, the ceramic elements were ok. It’s a bit tricky but if all fails at least you had a go.
Cheers
John

9th Sep 2018, 3:45 pm	#1
ramon56 Retired Dormant Member Join Date: Sep 2018 Location: Leeds, West Yorkshire, UK. Posts: 8	Dynatron GR14 Cordova stereo problem. Hope someone can help. I've got a Dynatron Cordova mono record player in really nice condition. However, when playing stereo records one channel is barely audible. I know this deck originally came with an optional extra speaker for stereo sound so I tried plugging in additional speaker but still you can barely hear one of the channels. Could this be just a stylus issue, or something more serious? Thanks

9th Sep 2018, 5:45 pm	#2
Edward Huggins Dekatron Join Date: Sep 2015 Location: Southwold, Suffolk, UK. Posts: 8,336	Re: Dynatron GR14 Cordova stereo problem. There's no point in plugging a speaker into the "stereo" socket on your Dynatron. You'll not get stereo, in fact you won't hear anything. This socket is for connecting a stereo adaptor unit (i.e. a amplified loudspeaker) for the RH channel. We need to know what kind of cartridge is fitted to your tone arm. It may be a stereo-compatible mono cartridge (2 connectors) in which case you will automatically hear both channels - or - it may be a stereo cartridge (4 connectors) which will need the LH and RH channels bridging. Please advise. __________________ Edward.

10th Sep 2018, 8:38 am	#3
ben Dekatron Join Date: Aug 2006 Location: Madrid, Spain / Wirral, UK Posts: 7,498	Re: Dynatron GR14 Cordova stereo problem. These usually came with a Garrard 3000 series deck and a Sonotone 9TAHC or Acos cart, both of which are stereo. If you're missing one channel, check first the connections at the cart rear - be very careful as the wires are very thin and can easily detach from the soldered tags if handled at all roughly. I do not know if these units have a make/break socket/plug contact for bridging the two channels to mono when not used with extension stereo amp/speaker (a la Bush SRP31) - that would be the next area to check. Perhaps someone here more clued in could advise on this point. __________________ Regards, Ben.

10th Sep 2018, 9:25 am	#4
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Dynatron GR14 Cordova stereo problem. The service data is available here:- https://www.service-data.com/product...12/1814/a11312 __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

11th Sep 2018, 8:58 am	#6
'LIVEWIRE?' Rest in Peace Join Date: Mar 2006 Location: N.W. Oxfordshire(Chipping Norton) Posts: 7,306	Re: Dynatron GR14 Cordova stereo problem. You've attached a picture of the stylus not the cartridge. The 'S' does indeed stand for Stereo. This simply means that the stylus tip is of a radius suitable for playing stereo records. The cartridge is the item into which the stylus clips, and will have a make/model no. similar to those suggested by Ben in post # 2, although it could be another make and model.

11th Sep 2018, 9:02 am	#7
ben Dekatron Join Date: Aug 2006 Location: Madrid, Spain / Wirral, UK Posts: 7,498	Re: Dynatron GR14 Cordova stereo problem. That looks like a BSR ST12/14/15 to me, though I've not seen one with the lettering embossed before. As suggested by LIVEWIRE, a picture of the cartridge in the arm would help. I suspect someone has replaced it at some point in time and not connected it up correctly. __________________ Regards, Ben.

13th Sep 2018, 11:18 pm	#9
ben Dekatron Join Date: Aug 2006 Location: Madrid, Spain / Wirral, UK Posts: 7,498	Re: Dynatron GR14 Cordova stereo problem. That's a Sonotone 52T. Very scarce outside the US. It may well be knackered like quite a few of this era now are. One quick test before condemning it. Put the volume about midway. Get a small jewellers metal screwdriver and , with the arm raised as in your first photo, gently touch each of the 4 contacts. On two there should be a loud ish buzz. Post back with findings. __________________ Regards, Ben.

14th Sep 2018, 4:52 pm	#10
ramon56 Retired Dormant Member Join Date: Sep 2018 Location: Leeds, West Yorkshire, UK. Posts: 8	Re: Dynatron GR14 Cordova stereo problem. Thanks Ben, I tried that and yes indeed, two of the wires buzz (the green and white if that makes any difference).

15th Sep 2018, 9:08 am	#11
John10b Nonode Join Date: Nov 2016 Location: Aberaeron, Ceredigion, Wales, UK. Posts: 2,887	Re: Dynatron GR14 Cordova stereo problem. Just a thought, you may be able to fix the Cartridge, could I suggest you take a look at some pictures on the thread “bass response....”. I opened a Sonotone cartridge and found corrosion on the pins, the ceramic elements were ok. It’s a bit tricky but if all fails at least you had a go. Cheers John