4343 Rotary switch

[Goldjazz]

I know there's been a bit said about how bad this switch is, I just want to add to that. I just pulled it out of my 4343B's and totally bypassed it. I'm running in biamp mode and there's quite an improvement without that damn switch. Greater clarity in the highs and more slam in the bass. It's pretty indistinguishable from the improvement i saw when going active 4 way. In fact I now think the improvements I saw between active 4 way and biamp were mainly due to not going thru that switch when Active 4 waying

Not sure if this thing was only used in the 4343's, but definitely recommend bypassing it if you haven't already. I won't go into it, but the thing is so poorly designed.

On another note, I also just side mounted them, actually rotating the baffle and everything. It's pretty cool.

[martin2395]

Yep, that switch is a dog. It was used on more models, 4333,44 and 45 for example.

[Goldjazz]

Yeah I was suprised how much it deteriorates the sound quality too. I had sprayed deoxit but those contacts don't contact properly in some areas on mine and were even shorting out on the screws that hold the thing in.

Yep, that switch is a dog. It was used on more models, 4333,44 and 45 for example.

[BMWCCA]

Happy to say my 4345 clones never had one!

[Goldjazz]

Happy to say my 4345 clones never had one!

Ha nice one.

[Mikhail]

I know there's been a bit said about how bad this switch is, I just want to add to that. I just pulled it out of my 4343B's and totally bypassed it. I'm running in biamp mode and there's quite an improvement without that damn switch. Greater clarity in the highs and more slam in the bass. It's pretty indistinguishable from the improvement i saw when going active 4 way. In fact I now think the improvements I saw between active 4 way and biamp were mainly due to not going thru that switch when Active 4 waying

Not sure if this thing was only used in the 4343's, but definitely recommend bypassing it if you haven't already. I won't go into it, but the thing is so poorly designed.

On another note, I also just side mounted them, actually rotating the baffle and everything. It's pretty cool.

It can be shown in the photo as it was done? What additional tools required? Should I had to solder?

[Goldjazz]

It can be shown in the photo as it was done? What additional tools required? Should I had to solder?

Sure I will take a photo. Basically just switch it to biamp mode if that's what you want. Remove the small panel with the switch attached (do not try to pull the switch apart). Every connection that the switch makes, you want to replace by de-soldering those wires from the switch and just soldering them to each other. There are a several wires that you can disconnect from the switch that are not used in biamp mode. In the end there will be no wires connected to the switch. Just leave the switch in there. Do one speaker first and check it against the other and check that it works, then do the other. For the woofers in biamp mode I just connect straight to the woofers by feeding a wire through the bass port. This can all be reversed if you want to put it back to normal for resale.

Tools: philips screw driver, soldering iron, solder, heat shrink. Yes I recommend only doing this if you have experience soldering. Its not hard but you dont want a bad solder joint. Takes about 30 mins per speaker.

[warpig]

It can be shown in the photo as it was done? What additional tools required? Should I had to solder?

Mikhail I saw this post and wanted to do mine. I wrote up a how to for the 4343B http://www.audioheritage.org/vbullet...ingle-amp-mode

[Wagner]

Mikhail I saw this post and wanted to do mine. I wrote up a how to for the 4343B http://www.audioheritage.org/vbullet...ingle-amp-mode

I am NOT suggesting that simplifying a signal path, any signal path isn't a "good" thing.............BUT, if the OP's switch looked like yours it is no wonder removing or by-passing them yielded an improvement in sound quality

I have a hard time believing that anyone owning a pair of speakers this nice would run them with a switch so heavily corroded; and DeOxit isn't going to clean up shit like that, not in a million years

That's 35+ years of crap on those contacts, what would you expect?! They've a layer of oxidation so thick it's a solid now and it's black!

Pain in the ass to service properly after all of these DECADES? Yes, can take hours to perform properly (I have to deal with them often with my ancient tube equipment, exactly the same switches) but extremely poor sonics blamed on the switch per se being used in that current state?

Hardly fair to blame the switch, proper, for that one; blame the real guilty party, Mother Nature

Exactly the same as the bad rap suffered by the old Aetna-Pollak controls; properly serviced, you'd never know they were there

Has anyone tried actually servicing one of these switches for the sake of comparison? (squirting a little contact enhancer doesn't count)

[Goldjazz]

Yep I agree with you, the sound quality improvement was due to the fact that it's really corroded (mine was even worse than warpigs). So yeah if was cleaned up and sweet it might be just as good. Thing is also after so many years of use there are other problems with mine. The contacts are riveted on at one point only, these had come loose and can actually rotate a bit, one was shorted on the mounting screw, they've also lost their bite a bit and don't make contact properly. I've decided I only want to biamp now, so no need for the switch.

I am NOT suggesting that simplifying a signal path, any signal path isn't a "good" thing.............BUT, if the OP's switch looked like yours it is no wonder removing or by-passing them yielded an improvement in sound quality

I have a hard time believing that anyone owning a pair of speakers this nice would run them with a switch so heavily corroded; and DeOxit isn't going to clean up shit like that, not in a million years

That's 35+ years of crap on those contacts, what would you expect?! They've a layer of oxidation so thick it's a solid now and it's black!

Pain in the ass to service properly after all of these DECADES? Yes, can take hours to perform properly (I have to deal with them often with my ancient tube equipment, exactly the same switches) but extremely poor sonics blamed on the switch per se being used in that current state?

Hardly fair to blame the switch, proper, for that one; blame the real guilty party, Mother Nature

Exactly the same as the bad rap suffered by the old Aetna-Pollak controls; properly serviced, you'd never know they were there

Has anyone tried actually servicing one of these switches for the sake of comparison? (squirting a little contact enhancer doesn't count)

[Wagner]

Yep I agree with you, the sound quality improvement was due to the fact that it's really corroded (mine was even worse than warpigs). So yeah if was cleaned up and sweet it might be just as good. Thing is also after so many years of use there are other problems with mine. The contacts are riveted on at one point only, these had come loose and can actually rotate a bit, one was shorted on the mounting screw, they've also lost their bite a bit and don't make contact properly. I've decided I only want to biamp now, so no need for the switch.

I understand
Broken, or if you do not need it, a switch, either way, can go
I wasn't calling you on your choice; they are your speakers
Just addressing the all too common phenomena in general (blaming parts as being bad when in fact it's the maintenance or lack thereof)

Really creates a headache (to use the example a second time) with AR restorations if you want them to retain their original sound and electrical characteristics (people just reflexively ripping them out)

[HCSGuy]

If it is just the UHF that is out, as Riley Casey said, it’s not the crappy rotary switch on the back of the speaker. However, it is highly likely you have an oxidized spot on the UHF potentiometer. When the speaker is playing, and you rotate the level adjustments on the front panel for each of the Midrange, HF, and UHF drivers, does the sound cut in and out, or is there smooth attenuation? My project for the last two weeks have been getting 43xx monitors out of storage and ready for listening, and I found problems with all of them, mainly scratchy pots, though there was an open capacitor on one of them causing no output from one driver. If you are still using the original crossovers, an open cap is definitely a possibility, but I’d clean the pot first.

Here’s how I did it. Get a can of De-oxit, a flashlight, and a small handheld mirror. Pull the woofer from the speaker, also the 2121, and the acoustic lens off the front of the speaker. Put a utility table (not a fancy dining room table with a center pedestal leg) against a wall so it wont move, then put a few thick towels or blankets on the table. Put the speaker face maybe a foot back from the table, facing the table, with some of the padding between it and the table, and maybe another foot of padding hanging down past the table edge. Then, lean the speaker forward against the table, and pick up the back of the speaker and shove it up onto the table, face down, but leave the woofer hole hanging off the edge of the table. Now you can sit under the speaker, use the mirror and flashlight to see the back of the potentiometers, and when you spray the De-oxit into the back vents on the pots, it will dribble down onto the contacts, instead of just out of the case. I try to give each pot two sprays in different holes, about 1sec spray each, then tip the speaker up and work the pots all the way back and forth about 5 times, then give each one one more shot, and rotate them again. I had pots that were completely dead and now work fine. Out of the 18 pots I’ve done this week, only one still has a spot where it mutes, but it’s all the way up, where I won’t use the pot. BTW, since you’re in there, clean all the pots. Also, De-oxit is not good for you, so make sure you ventilate the room. If the driver still doesn’t output at any level position, you’re going to have to crack open the crossover and test caps.

Btw, I am not keeping any of my 43xx monitors, but if I was, I would buy/build new crossovers for them - I’ve listened to all the drivers in a 4343 in project speakers with active crossovers for testing, and they are capable of much better sound than what I’m getting with the stock crossovers.

Good luck

[Dschonz]

I have a pair of 4343 monitors and recently lost the signal to UHF slot tweeter. The tweeter tests good. I thought it was a crossover issue, but when I turn the famous rotary switch to biamp, there is still no signal to the UHF. Any ideas? I will bypass the UHF attenuator next.

I am using 2235H for LF, re-coned 2121 for mid, the 2420 and 2405 are original. The bass is a bit loose and muddy and the midrange sounds quite veiled. I've tried 2122 and other mids with no improvement. Any suggestions would be welcome? And yes, the rotary switches look bad!

[Riley Casey]

When you say the tweeter tests good do you mean it passes signal or just shows continuity? Oxidation on the rotary bi-amp switch would affect more than just the super tweeter, it separates the woofer from all three upper range drivers and their crossover components. It might be a bad spot on the attenuator. The only fail mode in the crossover components would be an open capacitor, not impossible just a very rare occurrence. If you don't plan to bi-amp the speakers its best to jumper past the switch, if you do bi-amp the speakers its also good to jumper out the switch, the switch was a bad idea.

I have a pair of 4343 monitors and recently lost the signal to UHF slot tweeter. The tweeter tests good. I thought it was a crossover issue, but when I turn the famous rotary switch to biamp, there is still no signal to the UHF. Any ideas? I will bypass the UHF attenuator next.

I am using 2235H for LF, re-coned 2121 for mid, the 2420 and 2405 are original. The bass is a bit loose and muddy and the midrange sounds quite veiled. I've tried 2122 and other mids with no improvement. Any suggestions would be welcome? And yes, the rotary switches look bad!

[Goldjazz]

Hope you figured out the UHF issue. I once realised there was no UHF in one of my 4343's. Thought i blew the tweeter but when i looked inside it was a simple problem: i had inserted one of the wires to the tweeter a little too deep into the spring terminal and it was biting down on the insulation and not the exposed wire, hence no connection.