Player running too fast

[tubeboob]

:DThe good news first. Yesterday, I scored an Akai GXC 709 in mint cosmetic condition along with a JVC QL-F4 turntable with Pickering XSV 3000 cart, also in mint condition for a measly $40.00. The turntable works exactly as designed, sounds great etc.

:thumbsdn:The bad news. Despite its pristine appearance, the GXC 709 is running too fast. Voices sound higher pitched and 2 minute songs finish in about a minute and 45 seconds. Everything else works perfectly, FF Rew etc.

HELP. Any way to adjust the speed of the tape passing over the head? Remember now, I am mechanically challenged.

Cheers

[paolo]

There are any number of possible fixes, depending on the cause :)

Not as facetious a response as you might think. Many times, you can adjust motor speed by means of an adjusting screw on the motor. Usually a very small jewellers screwdriver is all you need, plus a steady hand.

The more correct approach is to figure out why its running fast in the first place and try to correct it.

Of course, I am not known for my correctness, so I'd probably check out the motor adjustment first. :D

[SaSi]

What I will say might sound Voodoo or something but I will voice it anyway.

When I buy an old unit that probably sat in a basement or shelf for years idling, if it even operates I am thankful. Then I take a crappy but working tape and run it on the deck several times. If it has auto repeat features I enable them and let it run overnight. Many problems solve themselves that way.

Of course it might be that someone fiddled with the adjustments playing around once the deck was decommissioned. You can check that by inspecting the cover screws. If they are in mint condition then most likely nobody messed around - otherwise anything goes.

Some capstan motors contain FG and speed control in their casing (larger ones) and might have a small trimpot in the back. Others (the ones typically connected by more than 2 cables to the PCB) are controlled by a circuit on the main PCB or a small motor control PCB. The circuit should be close to where the cable from the motor is soldered or socketed. Look for a trimmer, memorise or better take a picture of the current setting and then slightly turn it in both directions. If it changes speed - bingo!

The hardest part is calibrating speed, as you need a recorded tape of a known tone (1kHz or 3kHz) and a frequency counter to check that output is actually the frequency recorded.

[tubeboob]

Thanks for the quick replies.

I will first play tapes for an extended time, and if that does not work, I will try to find the adjustment screws and make some adjustments.

Once again, thanks much:thmbsp: