Defiant MP7 volume issues - UK Vintage Radio Repair and Restoration Discussion Forum

Growlerman · 28th Jun 2017, 5:59 pm

Hello

I've started having issues with my Defiant MP7 record player after it has been behaving itself after a deck refurb. The issue I'm having is that the sound is distorted and has a pumping action in that it goes slightly quiet and then comes back full strength. I have plenty of volume in fact when turned right down the audio can be clearly heard through the speaker.
I haven't replaced any components in the amplifier and by the looks of things it has never been touched since it left the factory.
There looks like 5 Plessey electrolytic capacitors 2 at 8uf and 3 at 100uf plus 2 1000uf smoothing capacitors. There is no hum and no bulging of the smoothing capacitors.
What would be my first step( I have downloaded the service info)

Thanks in advance
Dave

Station X · 28th Jun 2017, 6:04 pm

If the Plessey Electrolytic capacitors are of the red, yellow and black type, I'd recommend changing them.

Edward Huggins · 28th Jun 2017, 6:08 pm

This could be loose cartridge connections after the refurb to the deck. The cartridge is mono so check the 2 connectors and the pins for oxidisation. Use tweezers. Also spray the volume control with Servisol as the track may be worn. The amplifier is a quite straightforward 4 transistor design, but I would not touch this as yet.

Growlerman · 28th Jun 2017, 6:18 pm

Hi Graham
Yes they look like it.

Growlerman · 28th Jun 2017, 7:02 pm

Quote:

Originally Posted by Edward Huggins

This could be loose cartridge connections after the refurb to the deck. The cartridge is mono so check the 2 connectors and the pins for oxidisation. Use tweezers. Also spray the volume control with Servisol as the track may be worn. The amplifier is a quite straightforward 4 transistor design, but I would not touch this as yet.

Thanks Edward

I refurb the deck a few months ago and it has been in regular use since then and only started playing up this evening. I will double check the things you mention before changing components.

Growlerman · 4th Jul 2017, 6:26 pm

I have cured the "pumping volume" but have noticed that the service info states that the player has a BSR X1M cartridge but mine has a BSR X5H. I have plenty of volume intact even with the volume control turned right down sound is very audible through the speaker.
Does anyone know if it should have a high output cartridge like the one fitted or it should be a medium output device?
I don't know anything of the history of this machine as I bought it from a flea market a year or so. It all looks untouched.

Edward Huggins · 4th Jul 2017, 6:38 pm

The BSR X5H is definately the wrong cartridge for your Defiant and may even introduce distortion. It should be the BSR X1M or any comparable medium output stereo compatible cartridge. However, the good news it that the BSR X5H is worth a small fortune in its own right and these can sell for £40-50. They are ideal for Dansette type record players with very simple, low sensitivity, amplifiers.

Growlerman · 4th Jul 2017, 9:14 pm

Quote:

Originally Posted by Edward Huggins

The BSR X5H is definately the wrong cartridge for your Defiant and may even introduce distortion. It should be the BSR X1M or any comparable medium output stereo compatible cartridge. However, the good news it that the BSR X5H is worth a small fortune in its own right and these can sell for £40-50. They are ideal for Dansette type record players with very simple, low sensitivity, amplifiers.

Thanks Edward

What cartridge do you think would be suitable? Something like a X5M or SC12m?

I notice from Bens useful chart that the X5M is about 400mv and the SC12m about 190mv. The X5H seems to be about 1v so I do think that it is causing the distortion on loud records.

Edward Huggins · 4th Jul 2017, 10:54 pm

The BSR X5M would be the ideal choice. Do note, stocks of these must be running low by now. The sale of the X5H will cover this - if you do decide to sell it. However if you plan to buy another record player, say an early Dansette or Fidelity model, I would keep it to use on these.

Growlerman · 5th Jul 2017, 7:29 am

Quote:

Originally Posted by Edward Huggins

The BSR X5M would be the ideal choice. Do note, stocks of these must be running low by now. The sale of the X5H will cover this - if you do decide to sell it. However if you plan to buy another record player, say an early Dansette or Fidelity model, I would keep it to use on these.

Thanks for your advice Edward. I'll get an X5M and use the X5H on another project.

Dave

28th Jun 2017, 5:59 pm	#1
Growlerman Hexode Join Date: Mar 2008 Location: Northwich, Cheshire, UK. Posts: 313	Defiant MP7 volume issues Hello I've started having issues with my Defiant MP7 record player after it has been behaving itself after a deck refurb. The issue I'm having is that the sound is distorted and has a pumping action in that it goes slightly quiet and then comes back full strength. I have plenty of volume in fact when turned right down the audio can be clearly heard through the speaker. I haven't replaced any components in the amplifier and by the looks of things it has never been touched since it left the factory. There looks like 5 Plessey electrolytic capacitors 2 at 8uf and 3 at 100uf plus 2 1000uf smoothing capacitors. There is no hum and no bulging of the smoothing capacitors. What would be my first step( I have downloaded the service info) Thanks in advance Dave

28th Jun 2017, 6:04 pm	#2
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Defiant MP7 volume issues If the Plessey Electrolytic capacitors are of the red, yellow and black type, I'd recommend changing them. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

28th Jun 2017, 6:08 pm	#3
Edward Huggins Dekatron Join Date: Sep 2015 Location: Southwold, Suffolk, UK. Posts: 8,340	Re: Defiant MP7 volume issues This could be loose cartridge connections after the refurb to the deck. The cartridge is mono so check the 2 connectors and the pins for oxidisation. Use tweezers. Also spray the volume control with Servisol as the track may be worn. The amplifier is a quite straightforward 4 transistor design, but I would not touch this as yet. __________________ Edward.

28th Jun 2017, 6:18 pm	#4
Growlerman Hexode Join Date: Mar 2008 Location: Northwich, Cheshire, UK. Posts: 313	Re: Defiant MP7 volume issues Hi Graham Yes they look like it.

4th Jul 2017, 6:26 pm	#6
Growlerman Hexode Join Date: Mar 2008 Location: Northwich, Cheshire, UK. Posts: 313	Re: Defiant MP7 volume issues I have cured the "pumping volume" but have noticed that the service info states that the player has a BSR X1M cartridge but mine has a BSR X5H. I have plenty of volume intact even with the volume control turned right down sound is very audible through the speaker. Does anyone know if it should have a high output cartridge like the one fitted or it should be a medium output device? I don't know anything of the history of this machine as I bought it from a flea market a year or so. It all looks untouched.

4th Jul 2017, 6:38 pm	#7
Edward Huggins Dekatron Join Date: Sep 2015 Location: Southwold, Suffolk, UK. Posts: 8,340	Re: Defiant MP7 volume issues The BSR X5H is definately the wrong cartridge for your Defiant and may even introduce distortion. It should be the BSR X1M or any comparable medium output stereo compatible cartridge. However, the good news it that the BSR X5H is worth a small fortune in its own right and these can sell for £40-50. They are ideal for Dansette type record players with very simple, low sensitivity, amplifiers. __________________ Edward.

4th Jul 2017, 10:54 pm	#9
Edward Huggins Dekatron Join Date: Sep 2015 Location: Southwold, Suffolk, UK. Posts: 8,340	Re: Defiant MP7 volume issues The BSR X5M would be the ideal choice. Do note, stocks of these must be running low by now. The sale of the X5H will cover this - if you do decide to sell it. However if you plan to buy another record player, say an early Dansette or Fidelity model, I would keep it to use on these. __________________ Edward.