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Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment. |
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18th Apr 2019, 12:59 pm | #1 |
Octode
Join Date: Aug 2010
Location: Beeston, Leeds, West Yorkshire, UK.
Posts: 1,234
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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. |
18th Apr 2019, 4:12 pm | #2 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,787
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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.
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18th Apr 2019, 4:16 pm | #3 |
Octode
Join Date: Aug 2010
Location: Beeston, Leeds, West Yorkshire, UK.
Posts: 1,234
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Re: Dansette Conquest Auto iphone mod
I am guessing a line level input (earphone socket) but will get confirmation.
Gaz. |
18th Apr 2019, 5:03 pm | #4 |
Dekatron
Join Date: Mar 2008
Location: St. Frajou, l'Isle en Dodon, Haute Garonne, France.(Previously: Ellesmere Port, Cheshire, UK.)
Posts: 3,177
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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.
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18th Apr 2019, 5:45 pm | #5 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,787
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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.
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18th Apr 2019, 6:47 pm | #6 |
Dekatron
Join Date: Jun 2013
Location: East Sussex, UK.
Posts: 3,315
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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.
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18th Apr 2019, 8:30 pm | #7 |
Octode
Join Date: Aug 2010
Location: Beeston, Leeds, West Yorkshire, UK.
Posts: 1,234
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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. |
18th Apr 2019, 9:35 pm | #8 |
Dekatron
Join Date: May 2008
Location: Derby, UK.
Posts: 7,735
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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.
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20th May 2019, 9:58 pm | #9 |
Octode
Join Date: Aug 2010
Location: Beeston, Leeds, West Yorkshire, UK.
Posts: 1,234
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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. |
20th May 2019, 10:10 pm | #10 |
Rest in Peace
Join Date: Mar 2006
Location: N.W. Oxfordshire(Chipping Norton)
Posts: 7,306
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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.
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