Pioneer record deck - UK Vintage Radio Repair and Restoration Discussion Forum

112stereo · 9th Jun 2019, 1:16 pm

Can anyone help please ?
I am trying to repair a Pioneer PL470 record deck.
I have cleaned all the old grease and the mechanism is running smooth again.
Put a record on and the cartridge has no output !
Have checked all the wireing and it's ok from the cartridge socket to the amp plugs so must conclude the cartridge is faulty.
Had a look on the net and can't find a replacement anywhere.
Does anyone know if such a thing exists or am I wasting my time ?
The owner wanted it repairing for sentimental reasons and I was trying not to let her down.
Any help or advice would be appreciated.

govjohn · 9th Jun 2019, 1:58 pm

It would be very unusual for both channels of a magnetic cartridge to fail together as they are essentially two separate generators. I am not familiar with this deck, does it have muting contacts? These can fail and cause loss of signal. It's not too clear from the photo if the contacts to the cartridge are accessable, if they are touching them with a screwdriver with your finger on the shaft should produce a loud hum if the wiring is OK and disprove my original statement. Try it and see.
John.

ajgriff · 9th Jun 2019, 2:40 pm

I agree with John that complete failure of the cartridge is unlikely but not impossible I suppose. This looks like one of those Pioneer plug-in oddities with a side screw, made by Audio Technica. Finding a direct replacement may well be difficult and/or expensive. This one might be an option although technically for the PL-570:

https://www.ebay.co.uk/itm/Cartridge...8AAOSw65FXvLHn

A last resort might be to modify the tonearm head to accept the more conventional two hole cartridge type fixing.

Alan

Edward Huggins · 9th Jun 2019, 4:08 pm

This looks llke a budget deck that might have belonged in a "seperates" system.
The mounting is surely the 4TP and most commonly used on this class of deck.
If the cartridge does need replacing (but does it really?) it might be cheaper to buy an already working Japanese deck of similar specifications on ebay?

112stereo · 9th Jun 2019, 4:13 pm

I have removed the plug in head and physically touched the socket and I get a hum from each channel in turn.
I have also checked the negative leads for continuity.
Is it possable for the stylus to fail in this way, the tip is ok as it will track an L.P. with no issues as I can hear it in the groove.

112stereo · 9th Jun 2019, 4:20 pm

Hi ajgriff,
The link you sent looks almost identical to the one fitted.
I don't know what the difference in tone arms is, but thanks for that I am keeping a watch on it.

julie_m · 9th Jun 2019, 4:32 pm

If you get a hum from touching the connections at the tonearm end, that suggests the connection to the amplifier is sound.

Test the cartridge for continuity with a digital meter between L+ and L- and between R+ and R-.

There was one cartridge (ADC?) which actually had the magnet in the plastic stylus housing; and if that fell off, it would give no output.

112stereo · 9th Jun 2019, 4:57 pm

I have purchased a new stylus, either way it will come in handy later even if I need to purchase a new cartridge and you never know it MIGHT just clear the fault.

Will let you all know in a couple of days when it arrives.

ajgriff · 9th Jun 2019, 5:13 pm

Quote:

Originally Posted by Edward Huggins

The mounting is surely the 4TP and most commonly used on this class of deck ......

I think they are usually known as P-Mount or T4P cartridges. There appear to be a few US suppliers with typically high shipping rates but complete cartridges seem to be relatively uncommon in the UK.

Alan

ajgriff · 9th Jun 2019, 5:56 pm

If the cartridge itself does turn out to be faulty searching on Google or eBay using the term 'p-mount cartridge' returns a few alternatives. However, it's probably best to avoid the cartridges specifically designed for linear tracking arms.

Alan

Nickthedentist · 9th Jun 2019, 7:58 pm

Quote:

Originally Posted by ajgriff

Quote:

Originally Posted by Edward Huggins

The mounting is surely the 4TP and most commonly used on this class of deck ......

I think they are usually known as P-Mount or T4P cartridges. There appear to be a few US suppliers with typically high shipping rates but complete cartridges seem to be relatively uncommon in the UK.

Alan

True, but they turn up on a lot of entry-level 1980s Japanese turntables, including those supplied with the better class of stacking system. As such, there are loads floating around as "pulls".

I can certainly send you one FOC (probably with a duff stylus) if it really is the cartridge at fault, but I suspect this is not the case.

Have you measured the resistance of its coils, across each of the phono plugs, as suggested by Julie earlier?

Nick.

bikerhifinut · 9th Jun 2019, 9:59 pm

this looks similar
https://shop.mantra-audio.co.uk/acat...95.html#SID=12
Hope that may help.
Mantra are usually very helpful if you contact them direct for advice.

A

ajgriff · 9th Jun 2019, 10:08 pm

Since the hum test shows that there is continuity between the tonearm/cartridge socket and the amplifier I'd be thinking in terms of cartridge pin oxidation. If cleaning the pins makes no difference the next step would be to test the cartridge's pin-to-pin resistance with a DMM as already suggested.

If a replacement cartridge is needed I would take up Nick's generous offer as you will already have a new stylus by then. There may be loads of 'pulls' knocking around but they're not always easy to get hold of when you need one.

It would be good to get the deck working again as it has sentimental value for its owner.

Alan

Spec-chum · 9th Jun 2019, 10:51 pm

You may know this already, but are you sure your connecting the turntable to an amp that has a phono input for magnetic cartridges? A line level input won't do as these cartridges need a pre-amp. I'd of thought the buzz test if done through a pre-amp would be quiet startling even at low volume levels. Do you hear anything at all with the amp volume turned up high?

ajgriff · 9th Jun 2019, 11:14 pm

Good point and worth checking. I'd assumed, possibly wrongly, that the deck was being tested with whatever amplifier it was originally partnered with.

Alan

112stereo · 10th Jun 2019, 3:10 pm

Still waiting for the stylus to arrive and I am pinning all my hope that this is the problem as I have checked the cartridge and each channel reads 350 ohm, this was taken at the pins of the cartridge and again at the plugs for the amplifier. Earth to earth and positive to positive read infinity!
I did however change one if the Phono leads as it was intermittent, but it made no difference.
Just to make sure I plugged it into my amp and again I get no sound and my own Sony deck with a magnetic cartridge works great.

Will let you all know what happens when the new stylus arrives.
Thank you all so far with all the help and advice, it's always good to get assistance in case I've missed something.

Nickthedentist · 10th Jun 2019, 4:22 pm

My offer still stands, and I expect the new stylus will bring things back to life, but here's another P-mount cartridge which isn't too expensive new: https://www.amazon.co.uk/Technica-AT...gateway&sr=8-4

112stereo · 11th Jun 2019, 4:55 pm

Hi, Nickthedentest
I would love to take you up on your cartridge offer as the new stylus still doesn't work!
Not a clue what can be wrong with the fitted cartridge, I was convinced that the new stylus would work.

Clydeuk · 11th Jun 2019, 5:15 pm

Are you sure your Sony turntable doesn't have a built in preamp? Having a magnetic cartridge does not mean there is no built in preamp. Try plugging your Sony into a line level input on the amplifier like the CD input. If it sounds normal then there is a preamp in the turntable and the Pioneer won't work.

112stereo · 11th Jun 2019, 5:38 pm

No pre-amp I had to rewire it when I bought it.
Someone had cut the wires off.

9th Jun 2019, 1:16 pm	#1
112stereo Pentode Join Date: Jan 2014 Location: St Albans, Hertfordshire, UK. Posts: 215	Pioneer record deck Can anyone help please ? I am trying to repair a Pioneer PL470 record deck. I have cleaned all the old grease and the mechanism is running smooth again. Put a record on and the cartridge has no output ! Have checked all the wireing and it's ok from the cartridge socket to the amp plugs so must conclude the cartridge is faulty. Had a look on the net and can't find a replacement anywhere. Does anyone know if such a thing exists or am I wasting my time ? The owner wanted it repairing for sentimental reasons and I was trying not to let her down. Any help or advice would be appreciated. Attached Thumbnails

9th Jun 2019, 1:58 pm	#2
govjohn Pentode Join Date: May 2011 Location: Cardigan, Ceredigion, UK. Posts: 100	Re: Pioneer record deck It would be very unusual for both channels of a magnetic cartridge to fail together as they are essentially two separate generators. I am not familiar with this deck, does it have muting contacts? These can fail and cause loss of signal. It's not too clear from the photo if the contacts to the cartridge are accessable, if they are touching them with a screwdriver with your finger on the shaft should produce a loud hum if the wiring is OK and disprove my original statement. Try it and see. John. Last edited by govjohn; 9th Jun 2019 at 2:00 pm. Reason: Correction of spacing

9th Jun 2019, 2:40 pm	#3
ajgriff Nonode Join Date: May 2004 Location: Halifax, West Yorkshire, UK. Posts: 2,587	Re: Pioneer record deck I agree with John that complete failure of the cartridge is unlikely but not impossible I suppose. This looks like one of those Pioneer plug-in oddities with a side screw, made by Audio Technica. Finding a direct replacement may well be difficult and/or expensive. This one might be an option although technically for the PL-570: https://www.ebay.co.uk/itm/Cartridge...8AAOSw65FXvLHn A last resort might be to modify the tonearm head to accept the more conventional two hole cartridge type fixing. Alan

9th Jun 2019, 4:08 pm	#4
Edward Huggins Dekatron Join Date: Sep 2015 Location: Southwold, Suffolk, UK. Posts: 8,326	Re: Pioneer record deck This looks llke a budget deck that might have belonged in a "seperates" system. The mounting is surely the 4TP and most commonly used on this class of deck. If the cartridge does need replacing (but does it really?) it might be cheaper to buy an already working Japanese deck of similar specifications on ebay? __________________ Edward.

9th Jun 2019, 4:13 pm	#5
112stereo Pentode Join Date: Jan 2014 Location: St Albans, Hertfordshire, UK. Posts: 215	Re: Pioneer record deck I have removed the plug in head and physically touched the socket and I get a hum from each channel in turn. I have also checked the negative leads for continuity. Is it possable for the stylus to fail in this way, the tip is ok as it will track an L.P. with no issues as I can hear it in the groove.

9th Jun 2019, 4:20 pm	#6
112stereo Pentode Join Date: Jan 2014 Location: St Albans, Hertfordshire, UK. Posts: 215	Re: Pioneer record deck Hi ajgriff, The link you sent looks almost identical to the one fitted. I don't know what the difference in tone arms is, but thanks for that I am keeping a watch on it.

9th Jun 2019, 4:32 pm	#7
julie_m Dekatron Join Date: May 2008 Location: Derby, UK. Posts: 7,735	Re: Pioneer record deck If you get a hum from touching the connections at the tonearm end, that suggests the connection to the amplifier is sound. Test the cartridge for continuity with a digital meter between L+ and L- and between R+ and R-. There was one cartridge (ADC?) which actually had the magnet in the plastic stylus housing; and if that fell off, it would give no output. __________________ If I have seen further than others, it is because I was standing on a pile of failed experiments.

9th Jun 2019, 4:57 pm	#8
112stereo Pentode Join Date: Jan 2014 Location: St Albans, Hertfordshire, UK. Posts: 215	Re: Pioneer record deck I have purchased a new stylus, either way it will come in handy later even if I need to purchase a new cartridge and you never know it MIGHT just clear the fault. Will let you all know in a couple of days when it arrives.

9th Jun 2019, 5:56 pm	#10
ajgriff Nonode Join Date: May 2004 Location: Halifax, West Yorkshire, UK. Posts: 2,587	Re: Pioneer record deck If the cartridge itself does turn out to be faulty searching on Google or eBay using the term 'p-mount cartridge' returns a few alternatives. However, it's probably best to avoid the cartridges specifically designed for linear tracking arms. Alan

9th Jun 2019, 9:59 pm	#12
bikerhifinut Octode Join Date: Nov 2013 Location: Penrith, Cumbria, UK Posts: 1,993	Re: Pioneer record deck this looks similar https://shop.mantra-audio.co.uk/acat...95.html#SID=12 Hope that may help. Mantra are usually very helpful if you contact them direct for advice. A

9th Jun 2019, 10:08 pm	#13
ajgriff Nonode Join Date: May 2004 Location: Halifax, West Yorkshire, UK. Posts: 2,587	Re: Pioneer record deck Since the hum test shows that there is continuity between the tonearm/cartridge socket and the amplifier I'd be thinking in terms of cartridge pin oxidation. If cleaning the pins makes no difference the next step would be to test the cartridge's pin-to-pin resistance with a DMM as already suggested. If a replacement cartridge is needed I would take up Nick's generous offer as you will already have a new stylus by then. There may be loads of 'pulls' knocking around but they're not always easy to get hold of when you need one. It would be good to get the deck working again as it has sentimental value for its owner. Alan

9th Jun 2019, 10:51 pm	#14
Spec-chum Tetrode Join Date: Mar 2019 Location: Grantham, Lincolnshire, UK. Posts: 79	Re: Pioneer record deck You may know this already, but are you sure your connecting the turntable to an amp that has a phono input for magnetic cartridges? A line level input won't do as these cartridges need a pre-amp. I'd of thought the buzz test if done through a pre-amp would be quiet startling even at low volume levels. Do you hear anything at all with the amp volume turned up high?

9th Jun 2019, 11:14 pm	#15
ajgriff Nonode Join Date: May 2004 Location: Halifax, West Yorkshire, UK. Posts: 2,587	Re: Pioneer record deck Good point and worth checking. I'd assumed, possibly wrongly, that the deck was being tested with whatever amplifier it was originally partnered with. Alan

10th Jun 2019, 3:10 pm	#16
112stereo Pentode Join Date: Jan 2014 Location: St Albans, Hertfordshire, UK. Posts: 215	Re: Pioneer record deck Still waiting for the stylus to arrive and I am pinning all my hope that this is the problem as I have checked the cartridge and each channel reads 350 ohm, this was taken at the pins of the cartridge and again at the plugs for the amplifier. Earth to earth and positive to positive read infinity! I did however change one if the Phono leads as it was intermittent, but it made no difference. Just to make sure I plugged it into my amp and again I get no sound and my own Sony deck with a magnetic cartridge works great. Will let you all know what happens when the new stylus arrives. Thank you all so far with all the help and advice, it's always good to get assistance in case I've missed something.

10th Jun 2019, 4:22 pm	#17
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,841	Re: Pioneer record deck My offer still stands, and I expect the new stylus will bring things back to life, but here's another P-mount cartridge which isn't too expensive new: https://www.amazon.co.uk/Technica-AT...gateway&sr=8-4

11th Jun 2019, 4:55 pm	#18
112stereo Pentode Join Date: Jan 2014 Location: St Albans, Hertfordshire, UK. Posts: 215	Re: Pioneer record deck Hi, Nickthedentest I would love to take you up on your cartridge offer as the new stylus still doesn't work! Not a clue what can be wrong with the fitted cartridge, I was convinced that the new stylus would work.

11th Jun 2019, 5:15 pm	#19
Clydeuk Hexode Join Date: Mar 2012 Location: Liverpool, Merseyside, UK. Posts: 453	Re: Pioneer record deck Are you sure your Sony turntable doesn't have a built in preamp? Having a magnetic cartridge does not mean there is no built in preamp. Try plugging your Sony into a line level input on the amplifier like the CD input. If it sounds normal then there is a preamp in the turntable and the Pioneer won't work.

11th Jun 2019, 5:38 pm	#20
112stereo Pentode Join Date: Jan 2014 Location: St Albans, Hertfordshire, UK. Posts: 215	Re: Pioneer record deck No pre-amp I had to rewire it when I bought it. Someone had cut the wires off.