Teac V-6030 Wow & Flutter Reduction Attempt: Challenges & Discoveries

[@puremagnetics]

Keep your eyes on the wow/flutter spectrum window. 3.5 Hz - has a huge amplitude, this is, exceptionally, an inter-capstan belt. It is possible to reduce W/F by taking a batch (e.q. 10 pcs) of 125-128 mm x 5 mm belts from Ali and after find a turner which can help you to regrind the belts from 0.60mm to 0.45 mm of thickness with no thickness deviation and then just choose the better one basing on the 3.5 Hz harmonic height. As the result - the W/F should be around 0.04% WRMS. BTW the common frequencies, which are appearing in the W/F spectrum are the next: 1.2 Hz / 2.4 Hz - Right pinch roller (full or half turn) 1.3 Hz / 2.6 Hz - Left pinch roller (full or half turn) 3.5 Hz - intercapstan belt (for 128 mm) 3.7 Hz - intercapstan belt (for 115 mm, Direct Drive modification) 6.1 Hz - Right capstan/flywheel (if unbalanced) or, IMPORTANT! Capstan slippage between himself and right pinch roller. (these china rollers are a piece of ..... , so that's a normal behavior for them). Also 6.1 Hz may appear if the inter-capstan speed difference is too large, which is also a typical thing for Sankyo mech. (DD or belt-based). Usually it is around 0.4-0.7%, but should not exceed 0.25% (and done ONLY by elastic tension of belt itself)... This can be fixed by using 2 x 3 mm width belts placed togetner side-by-side (suitable only for DD mech) Or by grinding left flywheel (with help of turner), the way when: DL/dl = DR/dr (exactly, up to 0.00...) where dr - diameter of left capstan DL - diameter of left flywheel dr - diamter of right capstan DR - diamter of right flywheel 6.6 Hz - Left capstan/flywheel (for DD mech) 6.8 Hz - Left capstan/flywheel (for non-DD mech) 20+ Hz - take motor and gear unit.

[@hifirulezzz]

@puremagnetics I am not a Yaroslav. 3 different belts showed the same results with the same 3.5 and 7 Hz frequency. I polished and matted the capstan shafts again. I removed all bumps and blemishes from the capstan flywheel surface to make sure that belt will have even tension. At this moment I can think only about imbalanced capstans.

[@puremagnetics]

​@@hifirulezzz if the 6.1 Hz / 6.8 Hz harmonics are higher and 3.5 Hz is absent or comparably small, then we would talk about flywheels' imbalance. In your particular case - this is a belt (mostly) + too large intercapstan speed difference + possible rubber slippage relatively to the capstan on the right side as I stated before - due to poor quality of bushings inside these china pinch rollers. (trust me as a manufacturer of precision pinch rollers with ball-bearings with hundrets of hours tests of different china-pinch rollers as well). The only way to decrease W/F - grind the belt on the precision bench + decrease the diameter of the left flywheel according to the formula stated in the 1st comment. BTW - even the grinding of 1 belt might be not enough, since the heterogeneity of rubber's hardness around the circumference also affects the W/F, since the rubber is constantly going through a small diameter of pulley on the motor. Therefore, the only way - re-gring 10 belts and then choose the best one. Unfortunately.

[@hifirulezzz]

@puremagnetics these belts give me 0.022-0.027% at Pioneer or Sony decks. I doubt thin belts should be an issue. These Sankyo transports are a headache.

[@talbar1960]

Thank you, never owned TEAC, i all the time preferred Akai, SONY and Pioneer, but i dunno why))

[@cassettedeck-walkman-repair]

What i do when i run into these issues is take off the back tension belt and disable the left pinchroller (take the spring tension off) and test again The backtension belt , left pinchroller and left flywheel are known problematic sometimes but it gives you a few diagnostic hints

[@TucsonAnalogWorkshop]

I'm not sure if you said you tried a different motor? Sometimes that can make the difference.

[@hifirulezzz]

@TucsonAnalogWorkshop The speed was stable and if you take a look at the wow frequency it is 3.5 and 7 Hz - exactly as the rotation speed of the capstans.

[@bertheeren7250]

Did you try the Origin pinch rollers? I found the original rollers better in multiple Sankyos even if the replacements look better. Also, check if the pinch roller timing is correct. When lifting the head carriage the right pinch roller should turn before the left. Especially after replacing pinch rollers this can be off because the size of the replacement rollers is rarely what is should be.

[@asbcustom]

If you're still needing those capstans balanced, I can help you with that. I'd be interested to see if it helps.

[@EliasMeletiadis]

the v-8030 has exactly the same sankyo mechanism, except that in the 8030 the motor is controlled by a quartz controller.

[@jn3750]

SIR IS THE SIGLENT BETTER THAN THE HANTEK IN SIMILAR PRICE RANGE?

[@DJNeiloSF]

I'm curious why you didn't mention the motor as a source of the bad wow and flutter?

[@hifirulezzz]

@@DJNeiloSF motor will give a very different behavior. Will do speed change, wow on 30-40 Hz, etc, not on 3.5

[@timesurfer917]

I have this deck, last month it started to play slow.. then stopped playing. Forward and rewind still work and I can see both capstans are going round. And now it have developed a loud whirring motor sound. What could be the problem? Could it be a belt issue? It's far too complex for me to even attempt service myself.

[@Daveac100-i5k]

If capstans are moving fine it could be the back tension belt. The noise could be a result of it having no fixed belt.

[@Zomby3000]

It could be because of capstan’s motor. I think it should be replaced.

[@zambrano966]

Tuve una de estas, muy bonita, la vendi y luego me arrepenti.

[@andrewlittleboy8532]

I had two of these when they first came out and both had poor w&f. I eventually had a refund.