Low reed valve noise

[Morne]

When using mostly vinyl valves you are typically still required to use leather/vileda on the lower notes.

Are there any general rules regarding the point at which you switch from vinyl to thicker valves? Obviously if youre replacing existing valves of the same kind you can just follow what is already there. But what if youre coming from an all-leather setup? Or even just building from scratch?

I know there are opinions on the sound colour influence of the valves (e.g. by suppressing or highlighting harmonics). And there are also some other differences, like longevity, response, moisture absorption (as per Accordion Revival). I am not asking about those - I am interested in the noise aspect here.

In one of Toni Schwalls books he mentions that if the reed has a weight at the end then you definitely want to use leather/vileda. Also on the bass side you should try to use the same kind of valve within a rank because of the sound colour influence, i.e. dont switch over from vileda to vinyl halfway on one side of a block.

What Ive seen on both my 1950s Hohner Morinos is that on the treble side theyll have leather up to around E3 and after that they switch to vinyl. On the bass side theyll have leather on Bass 1 and Bass 2, and then vinyl on the chord ranks. In both cases leather valves are used beyond just those reeds with added weights. Toni Schwall also has some examples of instruments and where they go from leather/vileda to vinyl to nothing. They all seem to use leather a bit past those reeds with added weights.

So what exactly is the logic behind the noise aspect here? Ive got sets of vinyl valves that are large enough (and one that is even larger) than those low treble reeds. So technically speaking the valve will fit correctly, but I believe this is where the noise issue comes in. At some point the vinyl-only valve will be noisier, but why? Is this primarily due to the frequency of the reed, or more the physical dimensions of the reed or the valve?
For example, if I had a long, non-weighted low reed, would a sufficiently long vinyl valve be okay? Or would a thicker valve still be suggested?
Otherwise, do those longer vinyl valves perhaps have some very specific use case?

 

[Geronimo]

You are interested in the noise aspect of valves but not in the sound color influence. But those are the same thing since valve flutter noise is really occuring synchronously with the reed movement and thus contributes to its harmonics. Leather valves have considerably more inertia and their interaction when hitting the reed plate is just quiet. I dont actually know whether its the closed or the open valve that contributes more to the sound. For higher-pitched reeds, the closed valve is likely silent. Not so sure about the lower reeds.

Either way, Id suspect leather reeds to lower the pitch more than plastic valves because of their greater inertia but I havent found a reference with numbers and/or definite statement so far.

 

[Morne]

You are interested in the noise aspect of valves but not in the sound color influence. But those are the same thing since valve flutter noise is really occuring synchronously with the reed movement and thus contributes to its harmonics.

I was thinking more about the noise when the note stops playing (or is about to). Or if youre playing a low note and going in and out rapidly. I dont detect that buzzing noise while the note is playing, even if it is at that point responsible for the sound colour. Here I have the same low reed (not fully tuned), in the accordion, close to the microphone: . The first one is with a vileda + vinyl valve, the second one is with a vinyl-only valve. The buzzing at the end is more pronounced (even accounting for the fact that I didnt do both at quite the same volume).

Im currently looking at 3 different valve types (2 different kinds of synthetic + vinyl, and 1 vinyl-only) and Im curious as to why they make the vinyl-only valves up to a certain size if they are (theoretically) going to end up always being noisier than a corresponding thicker synthetic valve. If its meant for maintaining the sound colour across the entire low register then it makes sense, but otherwise Im trying to figure out what kind of reed, whether long and non-weighted low or long and not-so-low, would actually end up using it.

 

[debra]

This is one of the more difficult questions regarding accordion construction and repair, because it has such strong influence on the sound, in many ways.
Some new accordions are still being built with only leather valves, preferably *all* with metal boosters. In theory this should be optimal: sound will start more gradually and will also stop more gradually when you go softer and softer... and when playing notes in rapid succession there should be hardly any noise from the valves.
But that's the theory. In practice leather valves often do not close completely, laying entirely flat. You want the valve to be closed completely so that the opposite reed can start without the accordion first needing some air to suck that valve close. To have the valves all closed it is best to have these boosters, but they must also lay flat!
When you have this done perfectly you may find that the valves do not open enough. The leather may be too stiff and the booster may give too much resistance. Here is the real problem: finding a balance between the valve opening easily enough to open far enough even when you play softly, and the valve closing properly when the note stops playing. When the valve does not open far enough the frequency drops. And when it opens just a tiny bit you will hear that the note is struggling, so that's not too hard to detect. When you play louder the valve will open more, and as the airflow is then less restricted the frequency wants to go up, but the reed vibrating more also causes it to want to lower its frequency. When the balance is perfect the frequency will remain stable.
What about the plastic valves? They open more easily and further, and they close quickly and they close well. When you replace a leather valve with booster by a plastic valve the frequency will go up as the plastic valve offers less resistance. The frequency (tuning) may remain more stable over time than with leather valves whose resistance (and opening characteristic) may change...
When you hear a difference between two otherwise identical accordions: one with leather valves (for the higher notes) and one with plastic valves it is more likely due to an issue with the valves (most likely with the leather valves) than due to an intrinsic difference between the type of valves.

 

[Morne]

Here is an example of what Im talking about. This is the reed block where Ive been playing around with the different valves for the lowest treble notes (the wax is ugly because Ive been removing the reeds repeatedly):


The largest reeds are G2 - F3 and as you can see, those vinyl-only valves fit perfectly. But there is also another vinyl-only valve that is about 3mm longer:

Those would probably still fit one reed size larger, but then youre going even lower. The other two (shortened) valves are synthetic, with the darker one being slightly thinner.

When you hear a difference between two otherwise identical accordions: one with leather valves (for the higher notes) and one with plastic valves it is more likely due to an issue with the valves (most likely with the leather valves) than due to an intrinsic difference between the type of valves.

That is where Ive read differing opinions. Besides some online posts which I havent kept references for (maybe even on this forum), there is also Toni Schwall in his book Handharmonika-Instrumente: Instrumententechnik und Reparaturkunde, where he mentions that the material does influence the sound. Specifically, the rough surface of the leather absorbs the higher partials, whereas the smooth surface on the plastic valves reflects them, thus making the sound brighter. He then suggests that this might (in theory) be used by the manufacturer to modify certain reed banks to highlight or downplay those higher partials.
Interestingly, I did see some slight differences in the spectrum graph (in the tuner I use) when I switch between vileda and vinyl-only on the same reed, but I didnt do those checks in a rigorous scientific manner. In practice that probably doesnt say much and it would be better to compare two full identical instruments. However, figuring all that out isnt my goal for now.

 

[Geronimo]

Here is an example of what Im talking about. This is the reed block where Ive been playing around with the different valves for the lowest treble notes (the wax is ugly because Ive been removing the reeds repeatedly):
[ATTACHMENT NOT FOUND]

The largest reeds are G2 - F3 and as you can see, those vinyl-only valves fit perfectly. But there is also another vinyl-only valve that is about 3mm longer:
[ATTACHMENT NOT FOUND]
Those would probably still fit one reed size larger, but then youre going even lower.

Or you could just switch to a different reed quality. Those are machine reeds. Higher quality reeds tend to be made from harder steel and are longer and/or without weight at similar pitches. Partly I suspect those qualities to be lacking mostly in machine-milled reeds in order to let people hear the difference from the more expensively produced hand-made reeds, similar to how organically produced milk here is normalized on 3.8% fat content instead of 3.5% so that you can verily taste the difference of organically produced. Which is sort of whimsical since the principal importance is about improving the quality of the environment rather than the product but in a world of egomaniacs you need to link the two or youll not get anywhere.

So, uhm. You can have longer reeds at the same pitches. Just saying.

 

[debra]

My experience with the vileda (synthetic leather) reeds with plastic (vinyl?) boosters is that they give too much resistance. What I have done is to remove the plastic layers and add a metal booster instead.
The difference in sound that I observed with the vileda+plastic was caused mostly by the valve not opening far enough (producing a more muffled sound, and lower in frequency too) and the sound became brighter (and higher) when I replaced the booster.
It is of course true that leather may absorb a bit more of the higher overtones than plastic, but I believe that this difference is small compared to the difference in how far the valves open.

 

[Morne]

So, uhm. You can have longer reeds at the same pitches. Just saying.

Im aware of that. For example, that accordions bass G2 is longer and without added weight. But those bass reeds are also long enough that none of the plastic-only valves would fit, thus my question would not come into play there.

But even if all the low treble reeds were without added weights, its still not clear at what point you should not use plastic-only. For example, this randomly selected Bugari:


Only the first 3 reeds seem to have added weight. The other ones are just the original thickness of the steel. The photo isnt the clearest, but it looks like the longest plastic-only valves might just barely not be long enough to fully cover the next slots where leather is used.

I suppose Im looking for a rule where one does not necessarily exist, but something like use plastic-only until it no longer fits would be an acceptable heuristic, except that that doesnt seem to be the case from what Ive seen.

The difference in sound that I observed with the vileda+plastic was caused mostly by the valve not opening far enough (producing a more muffled sound, and lower in frequency too) and the sound became brighter (and higher) when I replaced the booster.

I noticed something related to that regarding how high up I glued the valves. I didnt glue the punched valves as high as the vileda valves (because of the extra glue space at the bottom) and there was definitely a difference in how far the valve opens. This might very well, as you said, play a role in the perceived effect on the sound. I plan on playing around with gluing the plastic-only valves higher up to see how that influences the buzzing noise.

 

[debra]

...
But even if all the low treble reeds were without added weights, its still not clear at what point you should not use plastic-only. For example, this randomly selected Bugari:
bugari-gold-plus-SN1-int-18.jpg

Only the first 3 reeds seem to have added weight. The other ones are just the original thickness of the steel. The photo isnt the clearest, but it looks like the longest plastic-only valves might just barely not be long enough to fully cover the next slots where leather is used.
...

In that Bugari its actually the first 9 reeds that have extra weight to the tip. The first 3 may have it added but the next 6 still have a heavier tip than the higher reeds. Still, only the first 6 reeds have a leather valve.

Im afraid you are looking for a rule where there is none. You do not have to switch from leather to plastic valves at all as all valves can be leather. But when you do switch, there is no rule that says where you should make the switch, or at least no rule Im aware of.

 

[debra]

I have just done a rewax and revalve of one side of a reed block (L reeds) and initially I tried to go with all plastic but the valve noise was bad on the low notes. My experience is now that below C3 (which is the first C on the M reed on a normal accordion, and the second C on the L reed) you should use leather valves (with boosters) or at least "vileda", not plastic. Higher up I find that plastic is fine in the sense that I cannot hear the noise of these smaller valves opening and closing any more than I can with leather valves. Whether this changeover can be heard I still need to check. I have 7 more sides to go...

Update: I can hear the difference where leather changes into plastic, but the difference is smaller than that between the white keys (still all leather) and the black keys (now leather changing into plastic). The position of the reed blocks (white keys exposed and black keys muffled a bit by the register mechanism) has more influence on the sound than the type of valves. And while I was bothered by the noise made by the plastic valves, the lowest three notes are also far from silent with leather valves...

 

[Morne]

Thanks for that update, Paul. That was the question I was trying to get at. As you mentioned there probably isnt much of a rule. I guess when converting leather-only to mostly plastic youll just have to play around to see what sounds acceptable on that specific instrument.

My experience is now that below C3 (which is the first C on the M reed on a normal accordion, and the second C on the L reed) you should use leather valves (with boosters) or at least vileda, not plastic.

How does that correspond with the weighted tips on your reeds?
Also, I assume those C notes are based on a typical CBA?

I ended up going with the plastic valves on all the low reeds I showed above. While I do hear a more noticeable valve slap/buzz on those low notes when changing bellows direction in the middle of a note (or bellows shaking), I figured that doesnt really bother me that much, because I wont be doing much of that anyway. Other than that I cannot really detect any noise while playing, and also with this specific instrument (80 years old) it is a bit pointless to be too adamant about silence.

 

[debra]

My experience is based on trial and error. I have vileda (synthetic leather valves with plastic boosters), real leather (used with metal boosters) and plastic valves, all in the same sizes. I have also tried the vileda with the plastic boosters removed and a metal booster instead. You just have to try to find what:
1) makes the least amount of noise and,
2) provides the right amount of resistance, meaning it must open far enough yet close completely when the note stops.
3) makes no noise when open, which can be caused by the valve vibrating in sync with the reed or flapping and striking the reed.
What's also important is the width of the valves. If they are too wide they may rub against the side of the resonance chamber and the air flow needs to push an unnecessarily wide valve open. If they are too narrow they may get sucked into the opening, thereby no longer stopping the airflow and causing bad noises.

Years ago when I had a Bugari bass accordion I noticed that a seemingly random combination of different types of valves (leather with metal boosters or vileda with plastic boosters) was used, but this must have been to optimize the performance. Now I have a Pigini bass accordion and it came with vileda with plastic boosters on all (of the larger) reeds. This was not optimal so essentially Pigini leaves it up to the player to figure out which notes give unwanted noises and need a different type of valve. Not a big problem for me as I have all the parts and skills to do repair this, but unacceptable for the average player who is simply stuck with a less than optimal instrument (and certainly unacceptable considering what these instruments cost!).

 

[jollyrogeraccordions]

I just want to add a couple of things to this.
1) Carini have a range of leather+plastic booster bass valves, which I have found to be v good (if a bit expensive), They can be fitted a bit faster because you don’t have to go back over the reeds a second time to fit booster springs.
2) booster springs can be adjusted (by putting in tiny kink with small flat nosed pliers). Adjusting booster springs is a good way to tweak the valve behaviour ( at least for the outside reed, unless you pop off a reed to do the inside one....and not all reeds with boosters have them on the inside reed).