Dansette Major Deluxe - too quiet - Page 3 - UK Vintage Radio Repair and Restoration Discussion Forum

Station X · 17th Aug 2018, 6:30 pm

That's an extract from the circuit available from VRSD (up top there).

RojDW48 · 17th Aug 2018, 7:09 pm

I am suitably chastised Graham - I came across the other while surfing the net and thought 'oh, that's handy and free!' Should have stuck to the known, reliable source.

Station X · 17th Aug 2018, 7:11 pm

No chastisement intended. I have the VRSD DVD, but if something I need isn't on it I look for a freebie.

RojDW48 · 17th Aug 2018, 7:44 pm

This thing is making me go cross-eyed. There is supposed to be a 3.3K resistor from g2 of the valve and I can't find it! I think I have tracked down the 120R (in the foreground) and the 1800pF cap is the grubby thing next to it in the rather poor pics - but where should I look for that 3.3K resistor?

Nuvistor · 17th Aug 2018, 8:10 pm

Is there a resistor across the points shown in the photo?

RojDW48 · 17th Aug 2018, 8:26 pm

Yes there is - thank you Frank - it's even the right one! I'm going to put it somewhere I can't see it for a few days and try to recover my sanity.....and eyesight!

RojDW48 · 21st Aug 2018, 11:16 pm

I have just ordered 1800pF 1000V caps from China (don't look at me like that.....it's a Dansette!) 20 X pcs - £1.42 - FREE postage. How on earth do they do that?

Boater Sam · 22nd Aug 2018, 8:21 am

I buy bits from China and have never had any problems with quality or price.
Some things have never turned up, but its rare. I have had complete items like dash cams that have been really rubbishy but components seem OK.
I have bought lots of polyfilm red cherry caps over the years and never had a failure, remarkable when you think that they cost pence, for a hundred!

As to pricing, I bought a car cigarette socket to usb power supply for 40p including post, astounding, when you think that the cheapest UK parcel post is now £2.95.

Heatercathodeshort · 22nd Aug 2018, 8:54 am

It must be realized that these single stage amps require a very high output cartridge to drive the output valve fully and they do.

TC8M = Medium output. Used the amps with preamplifier stage. ie ECL/UCL82 etc.

TC8H = High output 800/1000mv. Used in single valve amplifiers. ie EL/UL84.

TC8H/2 = Very high output around 1200mv. Used in single valve amplifiers with lower
gm output valves such as the EL/UL41.

I have a sheet somewhere giving the exact output of the BSR TC range of crystal cartridges. When I find it I will post.

It's my guess that the above problem is simply a faulty/low output cartridge. John.

RojDW48 · 22nd Aug 2018, 11:06 am

That tallies with the info I have on cart outputs John. The highest value cart I have to hand is the TC8M, which probably wouldn't be any louder than the worn out X5H in there. I can't think of a way of substituting an input that would test the amp - my sig gen died many years ago. Where would I look for a 1V input I could hear? Any ideas?

As for those inscrutable suppliers of components, I haven't had much experience but some years back I bought 2 motor run caps from China (for £1.47 inc P&P) and used one in an old rim drive deck - and that's still working well.

ms660 · 22nd Aug 2018, 11:16 am

If you are stuck for 1 volt input signal, potential divider across the heater supply, it will do the same as a buzz test but with a known "buzz" voltage.

Lawrence.

Edward Huggins · 22nd Aug 2018, 12:44 pm

Quote:

Originally Posted by Heatercathodeshort

It must be realized that these single stage amps require a very high output cartridge to drive the output valve fully and they do.

I have a sheet somewhere giving the exact output of the BSR TC range of crystal cartridges. When I find it I will post.

I lifted these from the Cartridge Thread above:

BSR TC8M = 400mV, TC8H/1 = 800mV and TC8H/2 =1.2V

Even so, I have never come across a TC8H/2 in 60 years.

John10b · 22nd Aug 2018, 3:07 pm

I took a look at Ben's sticky on cartridges and indeed the FulFi range: TC8M, TC8H/1 and TC8H/2 are listed, I wonder what colour difference is there between the 8H/1 and 8H/2? I do remember one being Red, that I think was the highest output, I could be wrong.
Cheers
John

RojDW48 · 22nd Aug 2018, 5:17 pm

Quote:

Originally Posted by ms660

If you are stuck for 1 volt input signal, potential divider across the heater supply, it will do the same as a buzz test but with a known "buzz" voltage.

That's a great idea! Looking at the Rs I have I could make R1 2 X 330R in series and R2 150R to get a bit over 1V from the heater supply. Does that seem sensible to you infinitely more knowledgeable members?

Edward Huggins · 22nd Aug 2018, 6:03 pm

I've still got this nagging feeling that you will end up with a cartridge problem - I do hope I'm proven wrong.....
If so, you need to think about what kind of cartridge you will need. If it's for Mono use only, there are newly re-manufatuctered ones now available. If you want Stereo Compatibility, you'll have more of a challenge.

Herald1360 · 22nd Aug 2018, 9:05 pm

Chinese cheapy and simple preamp (easily reversed) or change that EL84 for an ECL82 or the like and reengineer.

John10b · 23rd Aug 2018, 9:14 am

Edward could you tell me where to look for the mono cartridges please?
Cheers
John

Edward Huggins · 23rd Aug 2018, 11:04 am

Yes, it's called an HTC8. The original it's based on is a BSR TC8H. Easily found online. The cost is £35.00 - not sure about P&P.

BE WARNED: This is to be used for 78's and Mono 45's/LP's only. It will permanently damage Stereo LP's if they are played on this.

Station X · 23rd Aug 2018, 12:10 pm

You'll have to search on "HTC8 Cartridge" or all you'll get is mobile phones.

https://www.ebay.co.uk/itm/M-TC8-TC8...4AAOSwXtNaZvuT

Edward Huggins · 23rd Aug 2018, 2:02 pm

Thanks for the Link Graham. The OP should be aware that the one Posted above is for the Medium-Output version. H-TC8 Cartridge is the High-Output, Orange bodied type that will be needed.

17th Aug 2018, 6:30 pm	#41
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,286	Re: Dansette Major Deluxe - too quiet That's an extract from the circuit available from VRSD (up top there). __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

17th Aug 2018, 7:09 pm	#42
RojDW48 Nonode Join Date: Jun 2014 Location: Bristol, UK. Posts: 2,074	Re: Dansette Major Deluxe - too quiet I am suitably chastised Graham - I came across the other while surfing the net and thought 'oh, that's handy and free!' Should have stuck to the known, reliable source. __________________ '....don't go mistaking Paradise for that home across the road!' (Bob Dylan)

17th Aug 2018, 7:11 pm	#43
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,286	Re: Dansette Major Deluxe - too quiet No chastisement intended. I have the VRSD DVD, but if something I need isn't on it I look for a freebie. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

17th Aug 2018, 7:44 pm	#44
RojDW48 Nonode Join Date: Jun 2014 Location: Bristol, UK. Posts: 2,074	Re: Dansette Major Deluxe - too quiet This thing is making me go cross-eyed. There is supposed to be a 3.3K resistor from g2 of the valve and I can't find it! I think I have tracked down the 120R (in the foreground) and the 1800pF cap is the grubby thing next to it in the rather poor pics - but where should I look for that 3.3K resistor? Attached Thumbnails __________________ '....don't go mistaking Paradise for that home across the road!' (Bob Dylan)

17th Aug 2018, 8:10 pm	#45
Nuvistor Dekatron Join Date: Aug 2013 Location: Wigan, Greater Manchester, UK. Posts: 9,431	Re: Dansette Major Deluxe - too quiet Is there a resistor across the points shown in the photo? Attached Thumbnails __________________ Frank

17th Aug 2018, 8:26 pm	#46
RojDW48 Nonode Join Date: Jun 2014 Location: Bristol, UK. Posts: 2,074	Re: Dansette Major Deluxe - too quiet Yes there is - thank you Frank - it's even the right one! I'm going to put it somewhere I can't see it for a few days and try to recover my sanity.....and eyesight! __________________ '....don't go mistaking Paradise for that home across the road!' (Bob Dylan)

21st Aug 2018, 11:16 pm	#47
RojDW48 Nonode Join Date: Jun 2014 Location: Bristol, UK. Posts: 2,074	Re: Dansette Major Deluxe - too quiet I have just ordered 1800pF 1000V caps from China (don't look at me like that.....it's a Dansette!) 20 X pcs - £1.42 - FREE postage. How on earth do they do that? __________________ '....don't go mistaking Paradise for that home across the road!' (Bob Dylan)

22nd Aug 2018, 8:21 am	#48
Boater Sam Banned Join Date: Dec 2013 Location: Middlewich, Cheshire, UK. & Winter in the Philippines. Posts: 3,897	Re: Dansette Major Deluxe - too quiet I buy bits from China and have never had any problems with quality or price. Some things have never turned up, but its rare. I have had complete items like dash cams that have been really rubbishy but components seem OK. I have bought lots of polyfilm red cherry caps over the years and never had a failure, remarkable when you think that they cost pence, for a hundred! As to pricing, I bought a car cigarette socket to usb power supply for 40p including post, astounding, when you think that the cheapest UK parcel post is now £2.95. Last edited by Boater Sam; 22nd Aug 2018 at 8:25 am. Reason: added

22nd Aug 2018, 8:54 am	#49
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: Dansette Major Deluxe - too quiet It must be realized that these single stage amps require a very high output cartridge to drive the output valve fully and they do. TC8M = Medium output. Used the amps with preamplifier stage. ie ECL/UCL82 etc. TC8H = High output 800/1000mv. Used in single valve amplifiers. ie EL/UL84. TC8H/2 = Very high output around 1200mv. Used in single valve amplifiers with lower gm output valves such as the EL/UL41. I have a sheet somewhere giving the exact output of the BSR TC range of crystal cartridges. When I find it I will post. It's my guess that the above problem is simply a faulty/low output cartridge. John.

22nd Aug 2018, 11:06 am	#50
RojDW48 Nonode Join Date: Jun 2014 Location: Bristol, UK. Posts: 2,074	Re: Dansette Major Deluxe - too quiet That tallies with the info I have on cart outputs John. The highest value cart I have to hand is the TC8M, which probably wouldn't be any louder than the worn out X5H in there. I can't think of a way of substituting an input that would test the amp - my sig gen died many years ago. Where would I look for a 1V input I could hear? Any ideas? As for those inscrutable suppliers of components, I haven't had much experience but some years back I bought 2 motor run caps from China (for £1.47 inc P&P) and used one in an old rim drive deck - and that's still working well. __________________ '....don't go mistaking Paradise for that home across the road!' (Bob Dylan)

22nd Aug 2018, 11:16 am	#51
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Dansette Major Deluxe - too quiet If you are stuck for 1 volt input signal, potential divider across the heater supply, it will do the same as a buzz test but with a known "buzz" voltage. Lawrence. Last edited by ms660; 22nd Aug 2018 at 11:30 am.

22nd Aug 2018, 3:07 pm	#53
John10b Nonode Join Date: Nov 2016 Location: Aberaeron, Ceredigion, Wales, UK. Posts: 2,882	Re: Dansette Major Deluxe - too quiet I took a look at Ben's sticky on cartridges and indeed the FulFi range: TC8M, TC8H/1 and TC8H/2 are listed, I wonder what colour difference is there between the 8H/1 and 8H/2? I do remember one being Red, that I think was the highest output, I could be wrong. Cheers John

22nd Aug 2018, 6:03 pm	#55
Edward Huggins Dekatron Join Date: Sep 2015 Location: Southwold, Suffolk, UK. Posts: 8,326	Re: Dansette Major Deluxe - too quiet I've still got this nagging feeling that you will end up with a cartridge problem - I do hope I'm proven wrong..... If so, you need to think about what kind of cartridge you will need. If it's for Mono use only, there are newly re-manufatuctered ones now available. If you want Stereo Compatibility, you'll have more of a challenge. __________________ Edward.

22nd Aug 2018, 9:05 pm	#56
Herald1360 Dekatron Join Date: Feb 2007 Location: Leominster, Herefordshire, UK. Posts: 16,535	Re: Dansette Major Deluxe - too quiet Chinese cheapy and simple preamp (easily reversed) or change that EL84 for an ECL82 or the like and reengineer. __________________ ....__________ ....\|____\|\|__\|__\_____ .=.\| _---\__\|__\|_---_\|. .........O..Chris....O

23rd Aug 2018, 9:14 am	#57
John10b Nonode Join Date: Nov 2016 Location: Aberaeron, Ceredigion, Wales, UK. Posts: 2,882	Re: Dansette Major Deluxe - too quiet Edward could you tell me where to look for the mono cartridges please? Cheers John

23rd Aug 2018, 11:04 am	#58
Edward Huggins Dekatron Join Date: Sep 2015 Location: Southwold, Suffolk, UK. Posts: 8,326	Re: Dansette Major Deluxe - too quiet Yes, it's called an HTC8. The original it's based on is a BSR TC8H. Easily found online. The cost is £35.00 - not sure about P&P. BE WARNED: This is to be used for 78's and Mono 45's/LP's only. It will permanently damage Stereo LP's if they are played on this. __________________ Edward.

23rd Aug 2018, 12:10 pm	#59
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,286	Re: Dansette Major Deluxe - too quiet You'll have to search on "HTC8 Cartridge" or all you'll get is mobile phones. https://www.ebay.co.uk/itm/M-TC8-TC8...4AAOSwXtNaZvuT __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

23rd Aug 2018, 2:02 pm	#60
Edward Huggins Dekatron Join Date: Sep 2015 Location: Southwold, Suffolk, UK. Posts: 8,326	Re: Dansette Major Deluxe - too quiet Thanks for the Link Graham. The OP should be aware that the one Posted above is for the Medium-Output version. H-TC8 Cartridge is the High-Output, Orange bodied type that will be needed. __________________ Edward.