Philips N4510 input / output RCA mod

[NorfolkDaveUK]

As per the title , I have added a set of RCA sockets to my N4510 . What i would like to know is the following .

Which din socket should I be pulling from the signal from and which din would you use for line in recording?

I`m currently using 34 *see the pics and legend* but I have no record level control at all and input is really quiet . Playback via 34 is ok (muffled a bit but that`s probably down to it needing a service) its a bit of a confusing machine really , has lots and lots of sliders , that dont really do and awful lot unless you are using microphones and headphones .lol

Im thinking it might be better to use 31 for the output (monitor) ?!?!

Any help would be greatly appreciated.


EDIT : I`ve just noticed . mine has another socket next to 31 and 32 ? this one isnt listed in the manual . Any idea what that one is for ?

[NorfolkDaveUK]

OK so it would appear that this is a 4511 , even though it says 4510 on the front , the extra din is called BU12 and is marked as "test points" ? all a bit bizzare really .

I think I`ll go with tape out and aux in and see how that works out ... TA !

EDIT : ahhh..ok now i get the point of the test points ....thats a great idea. Why didnt they all do this ....lol

[TonyDuell]

The 'BU12' socket is shown on the circuit diagram I have for the N4510. I've never heard of the N4511, what are the differences? Incidentally, I think some Philips machines had 7 pin DIN sockets with the test points on pins 6 and 7 (the 'extra' pins). Just checked, the N4450 has said 7 pin DIN sockets.

I would take the line level output from the 'Monitor' socket (BU11), if only because the output on BU4 (Tape In/Tape Out) is muted other than in playback mode. I think this prevents you doing off-tape monitoring other than via headphones, which rather defeats the purpose of a 3-head machine. You could use the 'Tuner', 'Tape In' or 'Aux' sockets for line level input (they have slightly different characteristics), selecting the appropriate one with the slide switch on the panel. There is one slider to control the level for both channels, this is the right hand one in the bottom row of controls. If you have problems, the most likely cause is bad contacts on the input selector switch, these slide switches are known to give problems, I had to take mine all apart (in both the N4510 and N4450) and clean them.

[NorfolkDaveUK]

Thanks Tony ,
I dont see an awful lot of difference in the two apart from having 3 sockets where the manual is showing 2 on the 4510 , if you go to hfe there is an English manual for the 4511 which is the same ( it seems ) as the 10 , but having it now in English is a massive plus . The extras socket on mine is here : ( see pic )

[NorfolkDaveUK]

Yeah the switches on mine are dodgy too it seems . Great sounding machine though . I have to flick the switch back and forth a bit so they need cleaning for sure but once its right it sounds brill .

[TonyDuell]

Yes, that's my experience of those switches. I was getting channels missing and the like (on both the N4510 and the N4450). I found it best to take them apart -- remove the user control lever then take out the clip and pin from the little block on the switch slider that couple to the user control, take off the block and slide the switch slider out towards the other end of the switch. Re-insert it from that end too. If you try to remove/insert the slider from the end where the coupling block is, you will (by all accounts) damage the fixed contacts in the switch.

One you have it apart, clean both sides of the slider with propan-2-ol (isopropyl alcohol), then spray that into the switch body, insert the slider and work it back and forth several times. Take it out again and clean it again. Then put it all back together.

Apart from the switches (which to be fair are 40+ years old) these are great machines.

[NorfolkDaveUK]

I`m having a bit of an issue in that the recorded audio is a LOT quieter than the input audio . (using monitor out and aux in) input audio sound fantastic, recorded audio sound a bit pants . Better now I`ve cleaned the heads , but still way way quieter . None of the VR`s seem to be doing anything either which is a bit weird . Any suggestions ?

[NorfolkDaveUK]

Oh , here`s the 4511 manual btw in case you wanted to have a look .

https://www.hifiengine.com/manual_li...ps/n4511.shtml

[AndiiT]

Hi, traditionally most Philips machines of this "vintage" had a somewhat odd set up on the DIN sockets for input and output connections. In Playback mode the line level signal was available on Pins 3 (LH channel), 5 (RH Channel) and 2 (common ground or earth/screen).

On recording pins 1(LH) and 4(RH) were low level inputs expecting to see DIN standard signal levels of between 2 and 5mV or thereabouts in to around 47K, Pins 3 and 5 became Line level inputs expecting signal levels of between around 200 to 500mV into 10K. Monitoring signals (in the case of a three head machine) being provided by a seperate DIN socket.

One of the advantages of this design was that a standard "straight" (e.g. not reversed) DIN conection lead could be used when dubbing between two machines.

Regards

Andrew

[ms660]

Originally Posted by NorfolkDaveUK

None of the VR`s seem to be doing anything either which is a bit weird . Any suggestions ?

So far as I can make out, I don't think they will on playback unless you're using headphones.

Lawrence.

[NorfolkDaveUK]

Thanks (both of you ) . I`m going through the service procedure now I understand what the test socket is for , so far this is WAY off so someone has been in here "twiddling" . lol . Thankfully I have a scope and a sig gen so I`ll go through it one by one (slowly ..haha ) and see what pops out the other end . lol I think I`m going to re-cap it and get those switches sorted out first and then I`ll probably get some sense out of it . I have some new VR`s I can put in there too because they look like they died about 30 years ago too . Should sound great at the end of it all .


Thanks every one .

[TonyDuell]

Try the following settings and let us know what happens :

You don't need to have any tape loaded. Set the monitor switch (A and B positions) to 'B' for 'Before Tape' monitoring. This is the sort of monitoring you'd have on a 2-head machine, 'E-E mode' for VCR people. All slider controls to zero. Select 'S' (Stereo) on tbe track selector switch. Plug in an input and select the appropriate socket with that switch. Press and hold the record button, then press pause, then release them. This will put the machine into record mode without starting the tape transport. Slide up the 'REC' slider.

Do you get an indication on both level meters?

Can you hear the input signal with an amplifier connected to the Monitor socket?

[NorfolkDaveUK]

Cheers Tony . I`ll give that a try in a sec . Just stuffing my face mate . I`ll give it a whirl in a sec.

[NorfolkDaveUK]

Sorry , brain fart . Yes the input sound fantastic , on input (b) , but on tape monitoring (A) or playback of the tape , the levels are significantly lower .

[TonyDuell]

This suggets to me that the external connections are correct.

If you record on this machine, will the tape play back correctly on another machine? Conversely, will this machine play back a tape recorded elsewhere? You mention somebody had been fiddling, I would check the bias level, the 'recording unit' preset setting, etc.

[NorfolkDaveUK]

Yeah the settings are all over the place . The output level (A) SHOULD be the same as (B) , but its wayyy off . almost no movement on the meters at all on playback . Tapes recorded play back on the same way so the problem is with the output from the playback amp I think . My other working machine is a half track which makes things a little awkward . I have all manner of machines here but only one I can call reliable .

[TonyDuell]

Are you saying it will not correctly play back a tape recorded on another machine (or a pre-recorded commercial tape)?

If that's the case, it could be the playback units, along with the correction network on the speed switch PCB, the switch contacts for mode selection, the replay head, tape path, etc.

[julie_m]

I wouldn't go modifying the socket panel. You can still get leads with four phono plugs on one end of about a metre of cable and a 5-pin DIN plug on the other; all four signals (pins 1, 4, 5 and 3; 2 is common earth) are available from such a lead. Also shorter leads with about 15cm. of cable and four phono sockets. It's easy to trace which pin of the DIN plug goes to which phono using a multimeter. 1 and 3 (the outer pins) are used for the left-hand channel (or a mono signal), and 4 and 5 (the inner pins) are used for the right-hand channel, with adjacent pairs (1 and 4 or 3 and 5) being used together. Mono devices just use pins 1 and 3. A stereo microphone input might have 2 sockets; the LH one with pin 2=earth, 1=LH input, 4=RH input and the RH one with pin 2=earth and pin 1=RH input. This would work with either a single 5-pin plug carrying one signal on pin 1 and the other on pin 4, or two separate 3- or 5-pin plugs with signal on pin 1.

There are three sensible ways (and 57 silly ways!) you can wire two phono plugs to a 5-pin DIN plug, so I'd go for the four-way version every time just to save disappointment -- unless I knew for sure what I was buying was correct, as if it was a replacement for a known working lead. You could even start out with a 4-way adaptor and replace with the correct 2-way one once you were certain which connections were in use.

Per post 1, socket 31 should be an output, probably on pins 3 and 5; 32 is magnetic phono, 33 is ceramic phono or hi-Z line, but could be on pins 1 and 4 or 3 and 5. Turntables were also sometimes wired with the cartridge connections to 1 and 3, so this is something to watch out for; pins 4 and 3 may even be strapped internally on a phono input, to cope with either wiring. 34 seems to be a "universal" input and output (which will definitely need all 4 connections; probably 1 and 4 are low-Z in, 3 and 5 are hi-Z in during recording or outputs during playback) and 35 a lo-Z line input.

[NorfolkDaveUK]

I didnt modify the panel . I added 4 rca`s in side the cable cover . They work brilliantly . Monitor out and Aux in were the way to go and work great . Check the pics . Plenty of space in there for them . I hate selling something and then expecting people to have to go out and buy a lead . If I can do a little extra work and make like easier for people then I will . Now they have even more options.

[TonyDuell]

Yes, but now you can't split the machine into the 3 modules (deck, electronics, case+PSU) without desoldering, can you? Personally I would have simply provided a suitable cable or cables with the machine when selling it.

I hate buying things that others have modified in a way that removes a good design feature.