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Old 15th Mar 2018, 9:40 pm   #1
Kentode
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Default Akai GX4000D meets Quad 34!

First, the specifications.

Akai.

Din jack input 2mV
Output 300mV

Line out (phono)
In 70Mv
Out 0.775V

Quad
In (Tape replay) 300mV / max 13.5V 57Kohm imp
Out (To recorder) 300mV. 2.2Kohm imp.

Is that din jack input of TWO MILLIVOLTS correct?

I was hoping that as both pieces of equipment have din sockets it would be plug and play, but it might be better to use the four phono connections of the Akai to the din of the Quad.

Anybody using this combination?

All help gratefully received, thanks.
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Old 15th Mar 2018, 10:04 pm   #2
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Default Re: Akai gx4000d meets Quad 34!

Yes, that's microphone sensitivity because the DIN connector on the Akai goes into the mike input if I remember correctly. It was 1972 when I last used a friend's 4000D (this may be a strange coincidence, but a Mr J D Kent!)

Just try using the Quad with the phono connections on the 4000D. Tape to preamp is comfortable and preamp to tape is a bit strong but should be OK with the recording level knobs not turned up too much.

I remember making attenuators wanting to use DIN-Din cables for 4000D's

David
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Old 16th Mar 2018, 12:11 am   #3
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Default Re: Akai gx4000d meets Quad 34!

Hi Ken,
As you can see from the attached spec sheet the microphone jack sockets on the front of the machine are even more sensitive than the input on the DIN socket (0.25mV) but the output from the DIN socket is lower than that from the phono sockets so it would be less of a test for the Quad's input circuit, but that seems quite robust anyway. You can use the microphone's input pots to control the DIN input so long as there are no microphones attached - that's what it says in the user manual, I have no personal experience of this.
Cheers, Dave
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Old 16th Mar 2018, 12:55 am   #4
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Default Re: Akai gx4000d meets Quad 34!

Here's what the manual says about the DIN socket
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Old 16th Mar 2018, 10:49 am   #5
Kentode
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Default Re: Akai gx4000d meets Quad 34!

David, Dave, thanks to you both. I'm going to use the phono outputs.

Is it worth making any changes to the Quad 34 at the output to give me a better balance? I've got the circuit diagram (issue 2, 6001 onwards) but the resolution is too poor, sorry.

Edit. I think I've posted a clip of the input! I'm rushing! Back in about 4 hours.
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Old 16th Mar 2018, 6:23 pm   #6
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Default Re: Akai gx4000d meets Quad 34!

Right, I'm back. After two hours shopping in Bury, SWMBO now has all the handbags to match Emelda Marcos' shoes!

To sum up: tape to preamp comfortable - 0.775V to 0.300V.
Preamp to tape a bit strong - 0.300V to 0.070V.

Can the tape output be reduced by changing any of the components shown on the left-hand channel in the picture below? R17, C17, R26, R28.

I don't have the Quad to hand so I can't take any measurements with regards to E or I.
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Old 16th Mar 2018, 9:17 pm   #7
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Default Re: Akai gx4000d meets Quad 34!

From the Quad 34 manual:

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I imagine that the Quad service department would be able to help with the alternative "flags".

But first try it "as is". I found that the 300 mV tape outputs of both the Quad 44 and Quad 66 to be a good match to the 50 mV sensitivity line inputs of the Nakamichi BX-300 and CR-3 cassette decks, not requiring unreasonably retarded settings of their input gain controls.

2 mV sensitivity was not unusual for a DIN input. For example, the Revox A77 radio input (DIN socket) was 2.5 mV. With an appropriate impedance (33k in the Revox case), it was a reasonable match to the DIN "constant current" system. The latter has been much criticized, perhaps not unreasonably so, but consideration of its origins does invoke a modicum of forgiveness.


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Old 16th Mar 2018, 10:36 pm   #8
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Default Re: Akai gx4000d meets Quad 34!

Thanks Syncrodyne, I'll go and do some research into the DIN constant current system. Your insert shows CD, which my Quad 34 doesn't have (serial number 61xx), only AUX.

At the moment I'm really just thinking ahead, as I'm updating my 31 year old Hifi. I've had a Quad 34 /405 ll in storage for four years, which is about to undergo major surgery!

As you so obviously stated, I'll give it a go and hear what happens! As I've only been doing this for five years l like to err on the safe side!
Watch this space!
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Old 17th Mar 2018, 9:22 pm   #9
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Default Re: Akai gx4000d meets Quad 34!

Yes, you'll be better off using the four phono connectors rather than the DIN connector. The levels will be a closer match. Using the DIN connector would require you to add some resistors, and might increase noise as it involves attenuating the signal just to amplify it again. But if you did go that route, you could make up a switch box for feeding just the left or just the right signal to both amplifier inputs, or each side to it's own input, for listening to mono recordings on the upper or lower track, or stereo recordings, respectively. (The Akai's track switch doesn't do what you think it does.)
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Old 18th Mar 2018, 8:32 am   #10
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Default Re: Akai gx4000d meets Quad 34!

Thanks Julie, to be honest I've never used the track switching facilities but as I've been recording the latest Hitchhikers Guide on radio four l shall do some experiments.

Today is a duvet day on account of four feet of snow drifted against my front door - don't you just love the spring?
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Old 26th Mar 2018, 11:52 pm   #11
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Default Re: Akai GX4000D meets Quad 34!

I had endless problems trying to use the DIN socket on my Akai GX-4000D into a Quad 34. Performance has been excellent since changing to the phono sockets. If you search for “Audiophile 5 pin DIN to 4x phono” on eBay you’ll find the type of leads I bought. I used a continuity tester and the Quad DIN pinout in the manual to check which pairs of phono plugs on the cable were input/output and then labelled them to avoid future confusion.
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Old 27th Mar 2018, 8:31 pm   #12
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Default Re: Akai GX4000D meets Quad 34!

Thanks Wreck Tangle, I've got one and I've ordered two more.

Also I've obtained a QED headphones / speakers switch box to connect to the output of the Quad 405 2.
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Last edited by Kentode; 27th Mar 2018 at 8:33 pm. Reason: 5 pin din to 2 phono, not 4!
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