Help! Vibration noise with treble

[bobby_the_builder]

Hello everyone,

I recently bought a Soviet bayan (Rubin 6) online . However, I found a problem as I learned to play with both hands. The bass and treble are fine on their own, but whenever I play treble notes on the right hand side while playing bass notes on the left hand side, the treble (right hand notes) would vibrate and create this “flutter” noise (please see the links for the audio example). The vibration is too much to play any note smoothly.

https://whyp.it/tracks/239302/bayan-treble-vibration-problem?token=axsqb

I’m guessing there are a few possibilities:

1. Some problem with the bass reed or valve that is causing sympathetic vibrations?
2. Some problem with airflow fluctuations that is changing air pressure whenever I play bass notes?
3. Some problem with the treble reed? Maybe too sensitive
4. This I’m not too sure. Could a tuning issue cause this treble vibration?

However, I am pretty new to accordion/bayan and really don’t know what the cause is and how to fix it. Sadly there is no accordion repair service near me. Any insights would be greatly appreciated!

 

[debra]

The issue is not really bad judging from the sound sample. All accordions suffer from this to a different degree, typically not to a level that bothers anyone listening.
The problem is that the way accordion reeds work the reed opens and closes (very vast) while you play it, and that changes the air pressure inside (also very fast). When the reed is going through the reed plate it shuts off the air flow and when it is open (inside or outside the reed plate) it lets air flow and that reduces the air flow. All of this is happening so fast that the changes in air flow are not really influencing the treble reeds.
But with a low bass reed the changes (open and close happening between say 100 and 200 times a second for notes between 50 and 100 Hz) may be large enough to influence a higher treble note, especially if it is the same note some octaves higher, and not well in tune...
Besides this effect while notes are playing the starting and stopping of a large bass note may also cause a change in air pressure that you can hear in the treble notes.
But by far the most common cause of hearing a change in the treble note at the moment a bass button is pressed is caused by the player changing the pulling (or pushing) force on the bellows when pressing the bass buttons. It's hard to keep the pressure (pulling force) constant while pressing and releasing buttons.

 

[tcabot]

The sound file is no longer available.

Rubin 6 was an entry-level box with poor quality reeds (unless they were hot-rodded). Just about affordable for a regular Soviet Sergei to buy if he was serious about learning the bayan, but very rudimentary.

These boxes do tend to have an exceptionally sweet timbre, so at some point were very popular candidates for hot-rodding: re-building the treble keyboard with decent springs, coining & chiselling the reeds (also, might have to re-rivet some of them ), set up the clunky & horrible converter mech an viola - you've got yourself a very sweet sounding and sweet playing box. But these days it's the case of investing $1.5k of labour to get a sub $1k accordion.

If the problem you're referring to is that the treble note "falls through" when you press the bass, that's a very common issue with cheap, inefficient reeds. In my eyes it makes the box completely unplayable (you can't play legato) and is a problem with more than 50% of accordions you find for sale. This does not just apply to cheap & nasty Soviet boxes - it plagues a lot of the Italians as well.

That's why we pay thousands of yankee dollars for hand-made reeds.