PDA

View Full Version : Help with Ferrograph 4a.



DarrenHW
18-10-2015, 13:56
Picked this up the other day with some other gear:

http://i1324.photobucket.com/albums/u606/drtwas/IMG_5653_zpsi5e3rkeg.jpg (http://s1324.photobucket.com/user/drtwas/media/IMG_5653_zpsi5e3rkeg.jpg.html)

Everything seems to work except playback, as soon as play is engaged there is a loud hum which increases with the gain and I can only just hear what's being played back. Am I doing something stupid or does this point to more serious issues, if so I doubt I'll do anything with it but sell it as spares or repair.

Audio Al
18-10-2015, 17:12
Is the tape a known good one , Have you got the tape running through the correct path etc ?

DarrenHW
19-10-2015, 06:20
Hi Al,
Thanks for the reply, yes the tape has something on it (I have another R2R here to test), this is the path I've taken:

http://i1324.photobucket.com/albums/u606/drtwas/IMG_5695_zpsgozn7uh0.jpg (http://s1324.photobucket.com/user/drtwas/media/IMG_5695_zpsgozn7uh0.jpg.html)

I can at times hear what's on the tape but it's drowned out by the hum, which get's loud if I lift the top panel :scratch:.

Audio Al
19-10-2015, 08:15
If you are determined to get it sorted out and running as it should you could contact either

http://www.servicesound.com/tape.htm

or our very own

Lodgesound ( Stewart )

Old equipment like this needs a once over if being brought back into continued use , It WILL be worthwhile ;)

DarrenHW
19-10-2015, 08:23
Yes, I thought that may be the case :(. I don't have any need for it, so don't want to go through the expense, I only bought it as I was buying a number of other items and it was part of the deal. I would like a R2R but purely for decorative purposes (how sad is that!) and I'd really like an upright chromey one. Thanks for your help Al, but I hear eBay calling.

Firebottle
19-10-2015, 08:41
Sounds like it could be a broken wire on the tape head possibly?
Maybe the screen connection. Have a good look around the connections to the head, give the wires a gentle tug to make sure there isn't a break. Hopefully it might be something simple.

:)

Audio Al
19-10-2015, 08:43
PM me a price :eyebrows::)

DarrenHW
19-10-2015, 13:56
Sounds like it could be a broken wire on the tape head possibly?
Maybe the screen connection. Have a good look around the connections to the head, give the wires a gentle tug to make sure there isn't a break. Hopefully it might be something simple.

:)

Thanks for the advice Alan, I'll take another look when I have some time, I did check for anything obvious but worth another go.

337alant
19-10-2015, 17:31
Darren
+1 for what Alan suggested as that could definaily cause a loud hum
Dont know much about the 4a but you could try a couple of other things, I presume its valves?, if correct try re seating all of the valves and get the valves checked if possible.
The ferrograph will almost certainly have carbon resistors which can fail open circuit or drift well out of spec by now ?, caps are normally paper in oil so pretty reliable but check them anyway

Alan

Patrick Dixon
19-10-2015, 19:39
It looks great. Who cares what it sounds like?

DarrenHW
20-10-2015, 05:17
Darren
+1 for what Alan suggested as that could definaily cause a loud hum
Dont know much about the 4a but you could try a couple of other things, I presume its valves?, if correct try re seating all of the valves and get the valves checked if possible.
The ferrograph will almost certainly have carbon resistors which can fail open circuit or drift well out of spec by now ?, caps are normally paper in oil so pretty reliable but check them anyway

Alan

Thanks for the suggestions Alan, busy with work for the next few days but I'll hopefully be able to take another look at it later in the week.

Thanks all :).