1972 Sanyo G-2601kca music centre

[Jimmyhaflinger]

i got this old music centre from a relative who was going to throw it in a skip along with a load of old junk he had in his garage...

it was in really sad shape, the headshell of the BSR changer was broken and dangling from the tonearm, the changer itself was frozen due to hardened grease, the tape deck was totally dead, all switches and potentiometers were noisy to the point of being unusable, and the left channel sounded weak and very distorted.
also the aluminium trim plates on the tape deck were both badly bent by someone who peeled them off to gain access to the speed and azimuth adjustment holes below, then they were crudely glued back in place.

luckily i got an exact replacement headshell from a rusty BSR deck i had in my junk pile, then i cleaned and re-greased the changer mechanism... i needed the heat gun to free up the centre bearing and changer spindle assembly... i then fitted a new diamond stylus.
The cartridge has the same body as a BSR SX5 but has no markings on it and it's obviously not made by BSR, it seems to be ceramic since it still works after sitting in a damp garage for years, it also tracks better and with less tracking force, and has a much lower output and sounds much better than the original SX5, it sounds almost as good as a magnetic cartridge i'd say

The tape deck was dead due to both rec/play switch sliders being broken where a metal pin passed through them and one was stuck in the recording position, someone apparently forced them while reassembling the tape deck... incredibly, the broken bits were still inside the cabinet! i epoxied them back together then, re-lubed the mechanical auto-stop sensing lever which got stuck due to hardened grease and was preventing the heads from moving all the way into their working position... the deck works great now

The weak and distorted left channel was due to an open connection to the collector of an output transistor, the metal cased output transistor in this machine are mounted on the metal back panel along with the audio sockets, mains voltage selector and antenna connections, someone apparently turned the mounting bolt of a transistor, the nut and the solder lug behind it turned along with the bolt and the wire soldered to it twisted and then broke off the lug, i re-soldered it back in place the amp worked perfectly.

I don't think it was a good idea for Sanyo to leave the transistors exposed on the back panel, two of them have +30v on their metal case, it just takes someone who touches them with a grounded audio jack to fry the amp or the power supply.

By the way, the output stage is really strange, the PNP transistor is a Germanium 2SB474 and the NPN transistor is a Silicon 2SD24Y

i then cleaned all switches and potentiometers with servisol and replaced 3 burnt out source indicator lamps, then i straightened the bent aluminium plates by pounding them with a rubber screwdriver handle on a sheet of thick glass, they came out almost perfect, you can barely see the wrinkles under good lighting now.

By the way, this unit has a Showa date code inside: 47.9.20, which means september 20, 1972

i think it was worth the time it took, i really like these old Sanyo music centres, they're built very well, the amp is really powerful, i'd say at leas 20 undistorted watts per channel, as it runs on a single 30v supply, and i like their bold early 70s styling, i also have anoter one in perfect conditions from Feb. 1973 but with a Sanyo single play record deck instead of the BSR changer, and an updated output stage with plastic cased silicon transistors mounted inside the chassis.

[Jimmyhaflinger]

some more pictures, you can see the rec/play switches before and after i re-glued them back together, and the twisted black ground wires that broke off the lug on the collector of the left channel's 2SB474 transistor.

[Andrew2]

Gosh, I wish I had a tenner for every one of those I've repaired! They seemed to be everywhere in the 70's and 80's, and they were fairly reliable. IIRC, the main problems were dirty selector switches, noisy tuning gangs and the usual mechanical things (belts, lubrication etc) on the record deck and the cassette deck.

[Focus Diode]

Most interesting! I once had an almost identical unit, the only difference being it had a 2 speed semi automatic Sanyo rim driven turntable and not BSR. Think this also had a magnetic cartridge but stand open to correction if I'm wrong.

Well done on the excellent restoration.
Brian

[Jimmyhaflinger]

Originally Posted by Focus Diode

Think this also had a magnetic cartridge but stand open to correction if I'm wrong.

i think you actually had a G-2611, this was the later improved version built on the same basic cabinet and chassis, i think these were made until about 1976-77 or so, and by then their tape deck also got a tape counter and dolby NR

[Jimmyhaflinger]

update: i also had to replace the parallel zener diode and series resistor on the tape deck's supply rail with a MC7724 regulator to get the deck to perform decently...

the original parallel regulator got hot enough to darken the paxolin print around it, and was unable to keep the voltage from dropping way too much when the erase oscillator was working and the mains voltage was a bit too low

I guess that's why these music centres are notorious for their "hit or miss" recording ability

[clksteve]

Brilliant restoration. I have recently aquired a Sanyo G-206 KL With no previous knowledge but with help from the web I managed to get everything working although in truth it only needed the hard grease removing and switch cleaner on other bits. And the idler wheel I put in a drill and sanded the edge to get rid of a drumming noise caused by a groove worn in the edge. The only thing it needs to be perfect are 3 red source indicater bulbs. From your experience and memory is it a job an ameteur could do? I presume I would need to remove the whole thing from it's chassis as you describe earlier?
Many thanks, steve

[Hybrid tellies]

I have ways had a soft spot for Sanyo products. Great write up and brilliant restoration.

[Jimmyhaflinger]

Originally Posted by clksteve

The only thing it needs to be perfect are 3 red source indicator bulbs. From your experience and memory is it a job an amateur could do?

the little source indicator bulbs can be easily reached by removing the record deck

Originally Posted by Hybrid tellies

Great write up and brilliant restoration

it's been more than two years since i restored this music centre and had been using it almost daily since then

the tape deck's preamp finally failed for good a few month after i restored the music centre, leaky transistors i guess,

luckily i soon found a scrapped and ruined G-2601 and it had a perfectly working tape deck, which i fitted in my music centre along with the original zener regulator board, so now it's 100% original and working as new!

[samjmann]

I remember these units, for the most part the electronics were quite reliable.
On one unit I had I nearly broke the dial pointer trying to get the chassis out.
I never did work out how it came apart!

My uncle bought one in 1972, it has remained in the family since then still working! Every time I've seen it, I've thought one day I'll be asked to fix it!

I wonder how much of todays digital gear will be working 43 years from now?

SJM.

[Jimmyhaflinger]

i actually broke the dial pointer of my parts donor unit while trying to remove the faceplate from the chassis.

a bit of seriously poor design in an otherwise well made machine.