Akai 910 reel to reel recorder - valves - UK Vintage Radio Repair and Restoration Discussion Forum

AkaiRick · 13th Jul 2016, 2:54 pm

Hi,
I have an Akai 910 that I've owned from new (1968).
Six years ago I stored it in a shed in Cyprus (not ideal).
When I got it out recently, I found that the amplifier is not working.
The motor and mechanics are perfect but no sound. Apart from normal tape operation not working, I tested the Line In and Line Out functions and it's all dead.
I suspect that a valve/s may have failed.
The amplifier is the same as the other vintage Akai machines, M10, etc..
I'd appreciate any advice as to where I could get the valves tested and replaced, if necessary.
I'm in Westbury, Wilts

Station X · 13th Jul 2016, 3:39 pm

I'd say the problem is unlikely to be valve failure and replacing them or even getting them tested would be a waste of time and/or money.

First thing to check is whether the valves light up. If not they're unlikely to be all blown unless the recorder has been connected to the wrong supply voltage. It's easy to check heater for continuity using a DMM.

You should also check LT and HT voltages.

Station X · 13th Jul 2016, 4:01 pm

I've just looked at the Akai M10 manual and it's all transistor ie no valves. Are we at cross purposes here?

AkaiRick · 13th Jul 2016, 4:22 pm

Thanks Graham.
The valves all light up.
Rick

AkaiRick · 13th Jul 2016, 4:24 pm

Goofed again!
Thanks

AkaiRick · 13th Jul 2016, 4:29 pm

M-8. Two amplifiers on top of each other.
I think all Akai valve recorders were the same or similar.

Station X · 13th Jul 2016, 4:42 pm

If ALL the valves light up, including the rectifier, then all LT supplies are present.

The next thing to do is check for HT voltage across C25.

Circuit here:-

http://audiokarma.org/forums/index.p...t-down.460792/

AkaiRick · 16th Jul 2016, 12:06 pm

Thank you everyone. I shall use your expert advice when I'm next united with my 910.

So glad I joined!

13th Jul 2016, 2:54 pm	#1
AkaiRick Retired Dormant Member Join Date: Jul 2016 Location: Westbury, Wiltshire, UK. Posts: 6	Akai 910 reel to reel recorder - valves Hi, I have an Akai 910 that I've owned from new (1968). Six years ago I stored it in a shed in Cyprus (not ideal). When I got it out recently, I found that the amplifier is not working. The motor and mechanics are perfect but no sound. Apart from normal tape operation not working, I tested the Line In and Line Out functions and it's all dead. I suspect that a valve/s may have failed. The amplifier is the same as the other vintage Akai machines, M10, etc.. I'd appreciate any advice as to where I could get the valves tested and replaced, if necessary. I'm in Westbury, Wilts

13th Jul 2016, 3:39 pm	#2
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Akai 910 reel to reel recorder - valves I'd say the problem is unlikely to be valve failure and replacing them or even getting them tested would be a waste of time and/or money. First thing to check is whether the valves light up. If not they're unlikely to be all blown unless the recorder has been connected to the wrong supply voltage. It's easy to check heater for continuity using a DMM. You should also check LT and HT voltages. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

13th Jul 2016, 4:01 pm	#3
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Akai 910 reel to reel recorder - valves I've just looked at the Akai M10 manual and it's all transistor ie no valves. Are we at cross purposes here? __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

13th Jul 2016, 4:22 pm	#4
AkaiRick Retired Dormant Member Join Date: Jul 2016 Location: Westbury, Wiltshire, UK. Posts: 6	Re: Akai 910 reel to reel recorder - valves Thanks Graham. The valves all light up. Rick

13th Jul 2016, 4:24 pm	#5
AkaiRick Retired Dormant Member Join Date: Jul 2016 Location: Westbury, Wiltshire, UK. Posts: 6	Re: Akai 910 reel to reel recorder - valves Goofed again! Thanks

13th Jul 2016, 4:29 pm	#6
AkaiRick Retired Dormant Member Join Date: Jul 2016 Location: Westbury, Wiltshire, UK. Posts: 6	Re: Akai 910 reel to reel recorder - valves M-8. Two amplifiers on top of each other. I think all Akai valve recorders were the same or similar.

13th Jul 2016, 4:42 pm	#7
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Akai 910 reel to reel recorder - valves If ALL the valves light up, including the rectifier, then all LT supplies are present. The next thing to do is check for HT voltage across C25. Circuit here:- http://audiokarma.org/forums/index.p...t-down.460792/ __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

16th Jul 2016, 12:06 pm	#8
AkaiRick Retired Dormant Member Join Date: Jul 2016 Location: Westbury, Wiltshire, UK. Posts: 6	Re: Akai 910 reel to reel recorder - valves Thank you everyone. I shall use your expert advice when I'm next united with my 910. So glad I joined!