Dansette Prince - UK Vintage Radio Repair and Restoration Discussion Forum

Dorian27 · 3rd Jul 2018, 3:03 pm

Can any one help please. I have a Dansette Prince solid state Model no DRP30.
When I switch on and play a record the volume is very high with quite a hum, but after about 2 to 3 min it starts to go down. Also the hum fades as well but with that the sound deteriorates and becomes quite rattle, if that is the word. I would be most grateful if someone could help. Thanks

Diabolical Artificer · 3rd Jul 2018, 5:15 pm

The first thing to do is to remove the chassis and give it a good visual inspection and post some good close up pics here, obviously with the thing unplugged. It sounds like a capacitor will want changing at least.

It is not a good idea to plug a device of this age straight into the mains after it has not been powered up for a long time, you could cause a lot of damage. If nothing else build a lamp limiter, instructions are on this forum's main site.

What is your skill level? Do you know anything at all about electronics? Be careful, make sure it has been unplugged for some time before taking the chassis out or touching anything.

Andy.

Edward Huggins · 3rd Jul 2018, 11:03 pm

The DRP30 was a later (c.1969/70) Rank-Bush-Murphy made Transistor version of the earlier Dansette made "U" valve series Prince. I think when the OP said "rattle", he was meaning distortion. Sounds like a capacitor degrading in the voltage rail.

Dorian27 · 3rd Jul 2018, 11:11 pm

I know a fair bit about electronics. Not specialist by any means books and playing around with old radios and TV's back in the good old days. I will Take some pictures .and send them to you. I replaced a resistor today and for a while it played OK then slowly the volume went down not quite as low as before. he resistor was a 4.7k 10% right next to a transisitor.

Anyway thanks for responding, very grateful.

John10b · 4th Jul 2018, 8:51 am

Further discussions/information and circuit diagram with voltage readings on this rp can be found via “search” just put in rp details.
Cheers
John

Diabolical Artificer · 4th Jul 2018, 12:01 pm

"I know a fair bit about electronics." Ah, that'll make things easier, it's hard to know how to pitch answers for new members.

Post the pics here, there's a sticky describing the procedure here - https://www.vintage-radio.net/forum/...ad.php?t=77650

Andy.

Techman · 4th Jul 2018, 2:00 pm

Quote:

Originally Posted by Dorian27

Dansette Prince solid state Model

I'm not immediately familiar with this particular model, but being 'solid state' rather than valved, I think that capacitor trouble is maybe a little less likely in this instance.

From the fault description and the fact of there being that 'cooked' resistor, I would be suspecting thermal runaway with dodgy old Germanium devices - that's not to say that some electrolytic capacitors could also be on their way as well.

John10b · 4th Jul 2018, 2:38 pm

In the other “threads” I mentioned to you, a similar problem turned out to be the “quiescent control pot”, resulting in thermal runaway.
I don’t know how to link you to the thread, perhaps other members can help.
Cheers
John

John10b · 4th Jul 2018, 2:52 pm

A slightly quicker way to find thread is to simply put in Prince , in Search, and go to page 2.
You will see “Dansette Prince Sound Distortion.
Cheers
John

Techman · 4th Jul 2018, 2:55 pm

Quote:

Originally Posted by John10b

turned out to be the “quiescent control pot”, resulting in thermal runaway
John

Could well be, if it has one. Let's hope it isn't too late for those Germaniums, seeing as the OP keeps on running it until the sound goes off!

John10b · 4th Jul 2018, 4:12 pm

I was referring to the “thread”. Do you have circuit diagram for the DRP30?
Cheers
John

Station X · 4th Jul 2018, 4:52 pm

Quote:

Originally Posted by John10b

A slightly quicker way to find thread is to simply put in Prince , in Search, and go to page 2.
You will see “Dansette Prince Sound Distortion.
Cheers
John

Do you mean this thread:-

https://www.vintage-radio.net/forum/...d.php?t=112614

Why not post a link? It's much easier for people to find. Page numbers may be irrelevant as threads per page depends on individual settings.

Dorian27 · 4th Jul 2018, 5:20 pm

These are the pictures you wanted, I hope they are OK. This is the Dansette with sound problems a DRP30 Dansette Prince.

OK thanks.

ms660 · 4th Jul 2018, 6:00 pm

Looks like the same innards as a Bush SRP52 (Z109 board):

https://www.vintage-radio.net/forum/...9&d=1505047307

Amplifier setup in Post#10 and schematic in Post#12 in this thread:

https://www.vintage-radio.net/forum/...d.php?t=118777

Lawrence.

Dorian27 · 4th Jul 2018, 6:26 pm

The picture of the Bush SRP52 Z109 board. Can someone tell me the value and voltage of the large axial capacitor in the middle, and the small blue one if possible.

John10b · 4th Jul 2018, 7:22 pm

Yes Graham, thanks.
I’m not sure how to “post a link”.
Are we sure the DRP30 and the SRP52? uses same circuit, in a previous thread there was some doubt!
I note from the pictures there seems to be a pot on the pcb, could this be the one for adjusting the quiescent current which I referred to in previous post, there was some doubt this amp had one?
Cheers
John

ms660 · 4th Jul 2018, 7:39 pm

There's two preset pots, one for quiescent current and one for mid point voltage, you can see them on the board and also in the schematic.

Lawrence.

John10b · 4th Jul 2018, 7:54 pm

Thank you Lawrence, so no doubt then the circuit posted is for the Dansette Prince DRP30!
There you go Dorian plenty of information for you, see how you get on.
Cheers
John

Diabolical Artificer · 5th Jul 2018, 9:11 am

Looks like a damaged tropical fish cap 0.1u pic LHS or is it a hair?

A.

Dorian27 · 6th Jul 2018, 8:11 pm

Can any one tell me where I can get capacitors from as I have look on net for the value that they are and nothing at all on 2 of them 10uf 64v and I a 400uf 16v can’t see any one having these is there something else I can use or do any one know where I can get original ones thanks

3rd Jul 2018, 5:15 pm	#2
Diabolical Artificer Dekatron Join Date: Jul 2009 Location: Sleaford, Lincs. UK. Posts: 7,658	Re: Dansette prince The first thing to do is to remove the chassis and give it a good visual inspection and post some good close up pics here, obviously with the thing unplugged. It sounds like a capacitor will want changing at least. It is not a good idea to plug a device of this age straight into the mains after it has not been powered up for a long time, you could cause a lot of damage. If nothing else build a lamp limiter, instructions are on this forum's main site. What is your skill level? Do you know anything at all about electronics? Be careful, make sure it has been unplugged for some time before taking the chassis out or touching anything. Andy. __________________ Curiosity hasn't killed this cat...so far.

3rd Jul 2018, 11:03 pm	#3
Edward Huggins Dekatron Join Date: Sep 2015 Location: Southwold, Suffolk, UK. Posts: 8,327	Re: Dansette prince The DRP30 was a later (c.1969/70) Rank-Bush-Murphy made Transistor version of the earlier Dansette made "U" valve series Prince. I think when the OP said "rattle", he was meaning distortion. Sounds like a capacitor degrading in the voltage rail. __________________ Edward.

3rd Jul 2018, 11:11 pm	#4
Dorian27 Heptode Join Date: Jun 2018 Location: Carmarthenshire, Wales, UK. Posts: 564	Re: Dansette prince I know a fair bit about electronics. Not specialist by any means books and playing around with old radios and TV's back in the good old days. I will Take some pictures .and send them to you. I replaced a resistor today and for a while it played OK then slowly the volume went down not quite as low as before. he resistor was a 4.7k 10% right next to a transisitor. Anyway thanks for responding, very grateful.

4th Jul 2018, 8:51 am	#5
John10b Nonode Join Date: Nov 2016 Location: Aberaeron, Ceredigion, Wales, UK. Posts: 2,884	Re: Dansette prince Further discussions/information and circuit diagram with voltage readings on this rp can be found via “search” just put in rp details. Cheers John

4th Jul 2018, 12:01 pm	#6
Diabolical Artificer Dekatron Join Date: Jul 2009 Location: Sleaford, Lincs. UK. Posts: 7,658	Re: Dansette prince "I know a fair bit about electronics." Ah, that'll make things easier, it's hard to know how to pitch answers for new members. Post the pics here, there's a sticky describing the procedure here - https://www.vintage-radio.net/forum/...ad.php?t=77650 Andy. __________________ Curiosity hasn't killed this cat...so far.

3rd Jul 2018, 3:03 pm	#1
Dorian27 Heptode Join Date: Jun 2018 Location: Carmarthenshire, Wales, UK. Posts: 564	Dansette Prince Can any one help please. I have a Dansette Prince solid state Model no DRP30. When I switch on and play a record the volume is very high with quite a hum, but after about 2 to 3 min it starts to go down. Also the hum fades as well but with that the sound deteriorates and becomes quite rattle, if that is the word. I would be most grateful if someone could help. Thanks

4th Jul 2018, 2:38 pm	#8
John10b Nonode Join Date: Nov 2016 Location: Aberaeron, Ceredigion, Wales, UK. Posts: 2,884	Re: Dansette prince In the other “threads” I mentioned to you, a similar problem turned out to be the “quiescent control pot”, resulting in thermal runaway. I don’t know how to link you to the thread, perhaps other members can help. Cheers John

4th Jul 2018, 2:52 pm	#9
John10b Nonode Join Date: Nov 2016 Location: Aberaeron, Ceredigion, Wales, UK. Posts: 2,884	Re: Dansette prince A slightly quicker way to find thread is to simply put in Prince , in Search, and go to page 2. You will see “Dansette Prince Sound Distortion. Cheers John

4th Jul 2018, 4:12 pm	#11
John10b Nonode Join Date: Nov 2016 Location: Aberaeron, Ceredigion, Wales, UK. Posts: 2,884	Re: Dansette prince I was referring to the “thread”. Do you have circuit diagram for the DRP30? Cheers John

4th Jul 2018, 5:20 pm	#13
Dorian27 Heptode Join Date: Jun 2018 Location: Carmarthenshire, Wales, UK. Posts: 564	Re: Dansette Prince These are the pictures you wanted, I hope they are OK. This is the Dansette with sound problems a DRP30 Dansette Prince. OK thanks. Attached Thumbnails

4th Jul 2018, 6:00 pm	#14
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Dansette Prince Looks like the same innards as a Bush SRP52 (Z109 board): https://www.vintage-radio.net/forum/...9&d=1505047307 Amplifier setup in Post#10 and schematic in Post#12 in this thread: https://www.vintage-radio.net/forum/...d.php?t=118777 Lawrence.

4th Jul 2018, 6:26 pm	#15
Dorian27 Heptode Join Date: Jun 2018 Location: Carmarthenshire, Wales, UK. Posts: 564	Re: Dansette Prince The picture of the Bush SRP52 Z109 board. Can someone tell me the value and voltage of the large axial capacitor in the middle, and the small blue one if possible.

4th Jul 2018, 7:22 pm	#16
John10b Nonode Join Date: Nov 2016 Location: Aberaeron, Ceredigion, Wales, UK. Posts: 2,884	Re: Dansette Prince Yes Graham, thanks. I’m not sure how to “post a link”. Are we sure the DRP30 and the SRP52? uses same circuit, in a previous thread there was some doubt! I note from the pictures there seems to be a pot on the pcb, could this be the one for adjusting the quiescent current which I referred to in previous post, there was some doubt this amp had one? Cheers John

4th Jul 2018, 7:39 pm	#17
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Dansette Prince There's two preset pots, one for quiescent current and one for mid point voltage, you can see them on the board and also in the schematic. Lawrence.

4th Jul 2018, 7:54 pm	#18
John10b Nonode Join Date: Nov 2016 Location: Aberaeron, Ceredigion, Wales, UK. Posts: 2,884	Re: Dansette Prince Thank you Lawrence, so no doubt then the circuit posted is for the Dansette Prince DRP30! There you go Dorian plenty of information for you, see how you get on. Cheers John

5th Jul 2018, 9:11 am	#19
Diabolical Artificer Dekatron Join Date: Jul 2009 Location: Sleaford, Lincs. UK. Posts: 7,658	Re: Dansette Prince Looks like a damaged tropical fish cap 0.1u pic LHS or is it a hair? A. __________________ Curiosity hasn't killed this cat...so far.

6th Jul 2018, 8:11 pm	#20
Dorian27 Heptode Join Date: Jun 2018 Location: Carmarthenshire, Wales, UK. Posts: 564	Re: Dansette Prince Can any one tell me where I can get capacitors from as I have look on net for the value that they are and nothing at all on 2 of them 10uf 64v and I a 400uf 16v can’t see any one having these is there something else I can use or do any one know where I can get original ones thanks