UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Audio (record players, hi-fi etc)

Notices

Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment.

Closed Thread
 
Thread Tools
Old 18th Apr 2019, 12:59 pm   #1
tracypaper
Octode
 
tracypaper's Avatar
 
Join Date: Aug 2010
Location: Beeston, Leeds, West Yorkshire, UK.
Posts: 1,234
Default Dansette Conquest Auto iphone mod

Hi all.
I have had an inquiry asking if I am able to fit an Iphone mod to a two valve Dansette Conquest Auto. I read I may need a pre-amp but as I have not done this before and usually prefer to leave players original can someone please advise on how to do this and where to get a reasonably priced mod from.
Cheers.
Gaz.
tracypaper is offline  
Old 18th Apr 2019, 4:12 pm   #2
paulsherwin
Moderator
 
paulsherwin's Avatar
 
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,787
Default Re: Dansette Conquest Auto iphone mod

Do you want to add a simple line level input, or do you need to use Bluetooth? The latter is much more difficult, but modern iPhones don't have a headphone socket to provide an analogue audio source.
paulsherwin is online now  
Old 18th Apr 2019, 4:16 pm   #3
tracypaper
Octode
 
tracypaper's Avatar
 
Join Date: Aug 2010
Location: Beeston, Leeds, West Yorkshire, UK.
Posts: 1,234
Default Re: Dansette Conquest Auto iphone mod

I am guessing a line level input (earphone socket) but will get confirmation.
Gaz.
tracypaper is offline  
Old 18th Apr 2019, 5:03 pm   #4
Tractorfan
Dekatron
 
Tractorfan's Avatar
 
Join Date: Mar 2008
Location: St. Frajou, l'Isle en Dodon, Haute Garonne, France.(Previously: Ellesmere Port, Cheshire, UK.)
Posts: 3,177
Smile Re: Dansette Conquest Auto iphone mod

Hi,
As long as it's not a 'live chassis' design, it should be possible. But I imagine the Bluetooth approach would avoid any contact with the mains.
Cheers, Pete.
__________________
"Hello?, Yes, I'm on the train, I might lose the signal soon as we're just going into a tunn..."
Tractorfan is offline  
Old 18th Apr 2019, 5:45 pm   #5
paulsherwin
Moderator
 
paulsherwin's Avatar
 
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,787
Default Re: Dansette Conquest Auto iphone mod

It's not live chassis AFAIK. For a line input you just need to add a switched stereo 3.5mm jack socket before the volume control, with the stereo channels merged through a couple of 4.7k resistors.
paulsherwin is online now  
Old 18th Apr 2019, 6:47 pm   #6
vidjoman
Dekatron
 
Join Date: Jun 2013
Location: East Sussex, UK.
Posts: 3,315
Default Re: Dansette Conquest Auto iphone mod

Definitely check that the transformer is a fully isolated type. I’ve seen several Dansettes which have had a replacement amp fitted. (Well it’s a Dansette amp init, says the owner). You can’t rely on what the service data might suggest.
vidjoman is online now  
Old 18th Apr 2019, 8:30 pm   #7
tracypaper
Octode
 
tracypaper's Avatar
 
Join Date: Aug 2010
Location: Beeston, Leeds, West Yorkshire, UK.
Posts: 1,234
Default Re: Dansette Conquest Auto iphone mod

The guy says he wants to plug his iPhone in to play music through the speakers so this suggests the 3.5mm earphone jack.
The chassis has been earthed so just need to know what to do now?
Gaz.
tracypaper is offline  
Old 18th Apr 2019, 9:35 pm   #8
julie_m
Dekatron
 
Join Date: May 2008
Location: Derby, UK.
Posts: 7,735
Default Re: Dansette Conquest Auto iphone mod

Just connect the left and right signals, from the tip and middle contacts of the 3.5mm. jack plug respectively, via two equal-value resistors (any value 1kΩ or more will be fine) to the signal lead from the cartridge, and the screen to the cartridge earth. There is no need to disconnect the cartridge when using the auxiliary input, as its impedance is high enough not to affect anything. But you will need to unplug any external device if you want to listen to records.

You can route the lead through any convenient ventilation slot, if you don't want to drill a hole for a connector. But a 6.3mm. jack socket with a chrome bezel -- such as a repair shop might fit as an after-sale modification -- would not look out-of-keeping with the player. A stereo socket probably would be the "least surprising" choice.
__________________
If I have seen further than others, it is because I was standing on a pile of failed experiments.
julie_m is offline  
Old 20th May 2019, 9:58 pm   #9
tracypaper
Octode
 
tracypaper's Avatar
 
Join Date: Aug 2010
Location: Beeston, Leeds, West Yorkshire, UK.
Posts: 1,234
Default Re: Dansette Conquest Auto iphone mod

Managed to connect everything up for testing and it works a treat, My 19 year old son was well impressed, didn't think it could be done. He also has a modern iPhone with out the earphone socket but has bought a special adaptor for the charger socket and this works as well.
Any how, this Dansette Conquest is a single valve (ECL82) version not a two valve as I mentioned in my opening post and I connected via Two 4.7K resistors as suggested by paulsherwin, while the volume is good, could it be improved by reducing the resistors in value?
Cheers.
Gaz.
tracypaper is offline  
Old 20th May 2019, 10:10 pm   #10
'LIVEWIRE?'
Rest in Peace
 
'LIVEWIRE?''s Avatar
 
Join Date: Mar 2006
Location: N.W. Oxfordshire(Chipping Norton)
Posts: 7,306
Default Re: Dansette Conquest Auto iphone mod

The value of those resistors is open to experiment. In one adapter I made up for use with a mono car radio, I used two 4k7 pre-set pots, adjusting each for the best results, and to obtain equal volume from each channel. To some extent the value of resistor depends on the o/p resistance (impedance) of the iPhone and the i/p impedance of the Dansette's amplifier. Many years ago I remember being taught 'low into high by a factor of 10', i.e. if the o/p Z of the device being connected is, say, 5K, then the load into which it works should be 50k. Whether that's strictly true with a stereo source and a mono load, I'm not sure.
'LIVEWIRE?' is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 10:35 am.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.