Bush SRP31D - Restoration

[sawleyram]

Hi all, new member here with a record player I'm keen to restore and some questions to go along with that... As you'll guess from the title it's nothing rare but a model I'm very keen on having owned one in the past. I've only recently purchased it from a family who claim it was "very well looked after".

A bit more on the player itself...

When I took it home and powered it up there were a few apparent issues. While it powers up fine, plays records of all four speeds, demonstrates both valves illuminating and both the speaker and tweeter working fine there are issues playing records. It didn't play at a consistent speed and I notice a mild background hum when powered up (not noticeable when records are played) as well as the stylus picking up the sound of the platter rotating which I don't think is normal. It also occasionally skips on clean records too so at this point I'm thinking the stylus needs replacement which is straightforward enough. The wiring going to the stylus itself though is in poor condition (see photo) -- does anybody have suggestions on how to improve it? Each of the four wires have been stripped and re-joined and I think without solder. It's such a fine gauge of wire I don't know where to start.

Inside the player, it's generally nice and tidy: wires are sound, the tape still holds harnesses in place, etc. I found the platter mechanism/cogs contained the residue of rope/string which resulted in irregular movement. I removed the debris and this fixed the playing speed issue mentioned above. I believe this should now be greased?

Everything else seems fine. It packs a punch volume-wise but does seem a little quiet on one channel (left I THINK), but I'm hoping this is fixed by a replacement stylus.

Appreciate this is a bit of a ramble but I hope to find some advice!

[Nuvistor]

Lots of information in this thread. The deck will probably require a full clean and service. Grease goes hard but there is one point where grease should not be used. It a long thread so select the section that you need.
https://www.vintage-radio.net/forum/...ad.php?t=75401

[AndiiT]

Originally Posted by sawleyram

.......does seem a little quiet on one channel (left I THINK)....

Hi and welcome to the forum, looking at your pictures I think the coaxial plug on the Stereo/Amp socket needs to be inserted in the socket marked 'Stereo' and not 'Amp' - I'm not 100% certain on this without looking at my own SRP31D which is under a pile of stuff at present (I really need to tidy the workshop..) Swapping the connection won't do any harm to check.

Regards

Andrew

[Half a Mullard]

Hi and welcome

I have one of these players and they work very well. It is a mono machine so I think if one channel is faulty this will be down to the cartridge. That doesn’t look like the original to me, they would have been normally fitted with a Sonotone cartridge and that looks like a BSR one I think. I suspect the faults are due to the fitting of the replacement. The cartridge must be connected via push on solder tags, never solder directly to the cartridge. The wires are thin and need great care and patience when dealing with them. The hum is likely due to this. I would suggest check the connections very carefully, it does look as if the red wire is broken.

As an aside a very common fault with these players is the failure of the half wave rectifier which supplies the HT but possibly this might be a step too far at the moment! The player will still work even if the HT is low but best leave this for the time being. Another common fault is that the tweeter stops working but the elliptical speaker works very well on higher frequencies and in practice makes very little difference to the sound.

[Half a Mullard]

Regarding Andrew's point it does need to be plugged into the 'Amp' socket which is the one on the right.

(so it does look to be in the right one) Well worth checking though.

[Half a Mullard]

The wires are colour coded so one channel is red and black (red being the positive) and the other is blue and yellow with yellow being the positive. In practice it doesn’t matter which channel is which as they are connected together for mono reproduction.

[sawleyram]

Hi all, thanks a lot for the replies I'm really quite surprised and grateful of the responses.

I've checked which stylus is in it and it's a BSR SX6M (see attached picture), so Howard is absolutely spot on. I was pleased to see that the cartridge itself has not been soldered and does utilise the 'bullets' or push in connectors which are all sound and making a solid connection . It's just the wires I'm really concerned about and where I think the real problem lies -- wondering if it would be worth ordering replacement wire. I'm capable of doing this just not sure what gauge cable to use.

As you'll have seen from my last post the wires have been stripped and twisted together at some point so the insulation is missing. If I touch or pinch the twisted parts with the player on, the hum becomes louder so I think that must be at least part of (or if not the whole) cause of the issue.

I've found a new stylus (8TA) but I'm not sure if this will fit into the cartridge I have -- need to investigate that.

Thank you also to Frank. I did try to find a guide and with it being a fairly popular player I thought I'd find one, but clearly my search terms weren't good enough. Afternoon reading for me there thanks very much for the link.

[Techman]

Originally Posted by sawleyram

I've checked which stylus is in it and it's a BSR SX6M

It's just the wires I'm really concerned about and where I think the real problem lies -- wondering if it would be worth ordering replacement wire. I'm capable of doing this just not sure what gauge cable to use.

I've found a new stylus (8TA) but I'm not sure if this will fit into the cartridge I have -- need to investigate that.

A BSR SX6M is the cartridge that the stylus fits into and not the part number of the stylus - you must obtain the correct stylus for that particular cartridge.

The tone arm wiring has to be extremely thin and flexible so as to put negligible force on the arm as it tracks the record - it looks like someone has joined thicker wire to the original on yours. It's special wire and I don't think it's available, but check out specialist dealers such as 'Musonic' to see if they stock ready made up wiring, also for the correct stylus for your cartridge.

The electronics in your player are pretty much trouble free, using ceramic coupling capacitors, so no need to worry about that. The weak link is the rectifier, so it's worth checking the HT with a DMM on a high DC voltage range between the rectifier and the first smoothing capacitor, it should be a bit over 200 volts.

[Half a Mullard]

Hello again

I agree with Techman, the wire needs to be thin and flexible. I have some here which is stripped from, I think, old telephone cable. It is flexible, not solid core, possibly a little thicker than the original but not much as far as I can tell.

If it's of any use you are welcome to it for the cost of postage.

[Half a Mullard]

The 8TA stylus is almost certainly from the original cartridge which would have been a Sonotone, so wont be suitable.

You can obtain a BSR stylus from Musonic

https://www.musonic.co.uk/index.php?...ducts_id=32367

I've used them several times and can recommend them.

[ben]

That BSR SX6 cartridge you have is a good replacement for the Sonotone 8TA which the player came with, which have nearly all died by now. It will take the following flip over styli. Buy depending on whether you have or want 78 shellac discs:

ST12, ST14: one tip for vinyl, one for 78s
ST15: Two tips for vinyl
ST19: single tip for vinyl (Not flip over).

I would at least insulate the wires and see if that helps, but in the long term it woudl be advisable to replace them. Ond mouse and USB cables may yield some suitably thin cable.

[sawleyram]

Thanks, Ben -- I have ordered the ST12 from Musonic as I want it to be able to play both vinyl and shellac as it did originally.

Originally Posted by Techman

A BSR SX6M is the cartridge that the stylus fits into and not the part number of the stylus - you must obtain the correct stylus for that particular cartridge.

I should have written cartridge, not stylus! Thanks for the correction. On closer inspection today I've found the stylus doesn't sit straight within its cartridge -- it leans around 30 degrees towards the front of the player which I don't think is intentional. I won't be playing records on it until I have the new one. Thanks too for the heads up on things to note regarding electronics. I have made a note on these and further down the line of restoration I will check these parts out once I've fixed the wiring and received a new stylus.

Originally Posted by Half a Mullard

Hello again

I have some here which is stripped from, I think, old telephone cable. It is flexible, not solid core, possibly a little thicker than the original but not much as far as I can tell.

If it's of any use you are welcome to it for the cost of postage.

That's very kind of you, thank you. I did have some old cable from when I removed an extension socket in the house, but as it was before I started saving/hoarding everything in the garage (!) I binned it. Yours' has the right colours too which is great, If you're happy to post it out I'll give you £5 and the postage -- send me a message when you can.

In the meantime I did put a dab of solder on each of the joints and cover each wire in very fine sleeving. It's stopped the humming/crackling when touching the wires but not something I'd be happy to leave.

Now I've ordered a new stylus for my cartridge and look forward to being able to replace the wiring, I think that will make significant improvements to playback. Until then I'll keep her safely put away. As I do these jobs I'll record some pictures of the before and afters.

[Half a Mullard]

Glad you're making progress. I've looked at the wire again, it measures 1mm outside diameter so I think it should be OK. Also if I coil it neatly it should pop in an envelope so no need for postage although thanks for the kind offer. If you send me a private message with your address I'll gladly drop it in the post for you.

[sawleyram]

Thanks Howard I have sent you a message on this.

From a general perspective, this weekend I'll be cleaning out the area around the valves, speakers and volume controls. It's all very sound and intact but very dusty and grim. Some solvent, a toothbrush and patience required for this I think. Also need to clean and re-grease appropriate areas. Will post before and after pics for anybody interested in the general progress.

In the meantime and while using a test record (while I await a new stylus), I have managed to set up the tone arm positioning correctly -- before it was not returning to the right location at the end of play. I'm leaving the weighting until the new wires kindly sent from Howard are fitted.

[Edward Huggins]

Be aware of this kind of cleaning. It's purely cosmetic and will have no affect on the electrical performance - BUT - but it could cause an uneccessary disturbance which may be very hard to trace.

[Half a Mullard]

PM sent

Looks like you are making good progress. I'm not sure what the tracking weight is for that cartridge - I'd guess maybe 4 - 6g. Might be worth checking when you finish the wiring and fit the new stylus. You'll have probably seen the spring under the arm to adjust the tracking weight.

Hope it all goes well, please don't hesitate to let us know if we can help and please report on progress!

[Techman]

Originally Posted by Half a Mullard

I've looked at the wire again, it measures 1mm outside diameter so I think it should be OK.

Sorry to say that that'll be way too thick. I've measured genuine original pickup wiring and the outside diameter was around 0.51mm, so half the thickness and twice as flexible. You need to trust me on this when I say that the pickup wire where it passes through the arm pivot at the rear of the arm needs to be so thin and light that the arm doesn't know it's there as it tracks across the record. Using the wrong wire will end up with you spoiling your records, as the poor old wall of the groove will be working against that extra thick and un-flexible wiring (X4), so don't do it! Either look for the proper stuff or keep with the original with the joins, just so long as all four runs that go down through the arm pivot and bearing are the original thin flexible type - it doesn't matter about what actually runs along the arm itself, other than the fact that thicker wire will increase the tracking weight, which will need to be checked with a proper gauge and re-adjusted if necessary to prevent record damage.

I've never found a source of short lengths of that special wire, other than dealers such as Musonic occasionally having original made up wiring sets in stock - probably old stock that's been dug up from some closed down shop. You can probably buy it in bulk by the drum, but you'd need four drums for the four colours and that would probably cost hundreds as it's specialized and there's no call for it these days as far as I know. I've been down the road of old computer wiring such as old mouse cable inner wiring and at first glance it looks about right, but even it's too thick and not flexible enough. However, I did reluctantly use some on the tone arm of one of those crude cardboard box record players on which someone for some reason had completely ripped out the original wiring. It worked fine on that simple player, that by its very nature has a slightly heavier tracking weight to counteract the slightly thicker wire and would only be used for spinning old 45s and 78s, but I certainly would never consider using it on a decent record player such as the one that you've got.

I've not checked out old USB cable for thin inner wiring, but it could be a possibility, so that's something worth thinking about.

[sawleyram]

Originally Posted by Techman

Sorry to say that that'll be way too thick...

Thank you for the advice, that's the reason I joined this forum. So the small dabs of solder I've put onto the original wiring (plus the new insulation) -- surely this must weigh more than the weight of the replacement wire from Howard? Happy to be proven wrong I'm just trying to get my head around it... Would altering the tracking weight (with a gauge of course) to compensate for the extra weight not be enough to avert premature damage to my records?

I share you pain in not being able to find replacement cable though. I have managed to find short lengths of appropriate tonearm wire on eBay at ~£5.50 a length, but the lengths were too short (around 30cm) and they don't supply one of the colours.

I'm not sure I have a spare mouse I'd be willing to cannibalise! I'll have a look through my collection of computer cables though if the above really isn't possible.

[sawleyram]

Originally Posted by Edward Huggins

Be aware of this kind of cleaning. It's purely cosmetic and will have no affect on the electrical performance - BUT - but it could cause an uneccessary disturbance which may be very hard to trace.

Thank you.. There's quite a build up of dust/fluff which is thick in places. I'm sure it is largely cosmetic yes, but the dust around the valves (heat) must be a bit of a risk. I'll re-assess when I open the player up again given what you've said, but I will say I am aware of the delicacy of the parts.

[sawleyram]

Originally Posted by Techman

...just so long as all four runs that go down through the arm pivot and bearing are the original thin flexible type - it doesn't matter about what actually runs along the arm itself, other than the fact that thicker wire will increase the tracking weight, which will need to be checked with a proper gauge and re-adjusted if necessary to prevent record damage.

Apologies for another post (there's no 'edit post' option on this forum) -- I've just re-read your reply to me.

I think what you are saying is that I need to be aware of the limited space at the point where the tonearm is joined at the pivot. I have had a look at this and realise there is very little room to thread wire up from underneath the deck. The point being separate to the extra weight added onto the arm itself.

Will report findings this weekend.