Alexander Posted December 10, 2020 Share Posted December 10, 2020 Was looking to build a pair of AA's from scratch and looking into the tweeter protection of the (for now) OEM k77's. Checking with Crites for zener diodes and found they cost $100 for the set. Being that this price is way out of the price range to work with what have some of you used as an alternative? The OEM tweeters will be replaced early on so just can not justify the money spent. Thinking of polytechnics but what value would be used if they are an option? Quote Link to comment Share on other sites More sharing options...
babadono Posted December 10, 2020 Share Posted December 10, 2020 Wow! Even at Mouser they're $41.96 Jeesh. How about just going without, don't get too happy with the volume control until you replace the K77s? 1 Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted December 10, 2020 Share Posted December 10, 2020 5 minutes ago, Alexander said: The OEM tweeters will be replaced early on so just can not justify the money spent. Then leave the zeners out and don't run your amp at 11. As a temporary fail safe I've heard of people using small incandescent bulbs. Maybe someone will chime in and confirm. 1 Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted December 10, 2020 Share Posted December 10, 2020 1 minute ago, babadono said: Wow! Even at Mouser they're $41.96 Jeesh. How about just going without, don't get too happy with the volume until you replace the K77s? How about a polyswitch? Quote Link to comment Share on other sites More sharing options...
babadono Posted December 10, 2020 Share Posted December 10, 2020 how's about $25 a piece? https://www.rfparts.com/1n3996a.html Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted December 10, 2020 Share Posted December 10, 2020 2 minutes ago, babadono said: how's about $25 a piece? https://www.rfparts.com/1n3996a.html Tweeters will take 10 watts? Quote Link to comment Share on other sites More sharing options...
PrestonTom Posted December 10, 2020 Share Posted December 10, 2020 Those prices are certainly surprising. Using your AA crossover, you already have a 3rd order high pass on the tweeter so I would not worry about it (assuming you don't do anything outrageous). If you have a general interest in tweeter protection then do a search on some threads from DJK regarding "bulb protection" or something like that (if the power ran high, the signal was sent through a bulb, to dissipate the power). -Tom 1 Quote Link to comment Share on other sites More sharing options...
babadono Posted December 10, 2020 Share Posted December 10, 2020 How about 5 watt just for some safety? 48 cents a piece. https://www.mouser.com/ProductDetail/Micro-Commercial-Components-MCC/1N5338B-TP?qs=O2qRfqcg9D9h8Rr8o5cE%2BA%3D%3D I'll bet those 10 watt metal stud parts were a lot cheaper back in the day, supply and demand etc.... Quote Link to comment Share on other sites More sharing options...
Alexander Posted December 10, 2020 Author Share Posted December 10, 2020 48 minutes ago, Alexander said: Was looking to build a pair of AA's from scratch and looking into the tweeter protection of the (for now) OEM k77's. Checking with Crites for zener diodes and found they cost $100 for the set. Being that this price is way out of the price range to work with what have some of you used as an alternative? The OEM tweeters will be replaced early on so just can not justify the money spent. Thinking of polytechnics but what value would be used if they are an option? polytechnics ? where did I get that? Ment to say polyswitch 🙄 And I am by no means a cranker - so maybe I could get by with out them. Just want to keep the OEM AA xovers untouched . Quote Link to comment Share on other sites More sharing options...
babadono Posted December 10, 2020 Share Posted December 10, 2020 15 minutes ago, CECAA850 said: Tweeters will take 10 watts? Yea I don't think so and that was/is the problem. The back to back zeners will clamp the voltage at about 12V peak to peak. That will limit the power to about 2.25 watts RMS in the tweeter. Quote Link to comment Share on other sites More sharing options...
Marvel Posted December 10, 2020 Share Posted December 10, 2020 4 hours ago, PrestonTom said: If you have a general interest in tweeter protection then do a search on some threads from DJK regarding "bulb protection" or something like that (if the power ran high, the signal was sent through a bulb, to dissipate the power). I know that John Albright's DHA2 crossover had a #561 bulb in it. Bulb technology has changed a lot, so the same #561 can now be a halogen, L.E.D., or older filament bulb. I may have some of Dennis' notes where he says what bulb to use. The bulb goes in series with one leg of the tweeter, and as the current to the tweeter goes up, past a certain point, the filament will actually light up (the resistance goes up with a tungsten filament as the current goes up... almost zero resistance when cold, which is why most bulbs blow when they are first turned on.). Some people say you can tell it's in the circuit, and some can't tell. PE sells them for crossovers: https://www.parts-express.com/speaker-crossover-tweeter-protector-lamp--260-231 BTW, I think Community Light and Sound used to use bulbs in their crossovers, and they were placed in the cabinet where they could be seen from the mix position during concerts, so the sound man/woman knew to turn the gain down a little. I thought the K77 was only good up to about 5 watts. 🤔 1 Quote Link to comment Share on other sites More sharing options...
Deang Posted December 11, 2020 Share Posted December 11, 2020 NM. Quote Link to comment Share on other sites More sharing options...
Marvel Posted December 11, 2020 Share Posted December 11, 2020 @Deang Awe... Go ahead and say it. The tungsten filaments sound aweful... 🙄 Quote Link to comment Share on other sites More sharing options...
henry4841 Posted December 11, 2020 Share Posted December 11, 2020 On 12/10/2020 at 10:56 AM, babadono said: How about 5 watt just for some safety? 48 cents a piece. https://www.mouser.com/ProductDetail/Micro-Commercial-Components-MCC/1N5338B-TP?qs=O2qRfqcg9D9h8Rr8o5cE%2BA%3D%3D I'll bet those 10 watt metal stud parts were a lot cheaper back in the day, supply and demand etc.... Those should work just fine. In real world the tweeters should never see more than a few watts. My original Xovers did not have the zeners. After kids blowing a few tweets over the years I just fused my speakers with a fast blow 1 -1/4 amp fuse and never blew a tweeter again. Another option is to just buy a set of Crites tweeters and never worry about them again. Quote Link to comment Share on other sites More sharing options...
Alexander Posted December 12, 2020 Author Share Posted December 12, 2020 @henry4841the end game will be replacing the OEM k77s with something like Crites tweeters. Just want to do things one step at a time. Had learn that the hard way years back in drag racing days. 1 Quote Link to comment Share on other sites More sharing options...
Peter P. Posted December 12, 2020 Share Posted December 12, 2020 18 hours ago, henry4841 said: Those should work just fine. In real world the tweeters should never see more than a few watts. My original Xovers did not have the zeners. After kids blowing a few tweets over the years I just fused my speakers with a fast blow 1 -1/4 amp fuse and never blew a tweeter again. Another option is to just buy a set of Crites tweeters and never worry about them again. That was going to be my suggestion. Fuses are a cheap, effective solution. Of course you'll have to find which fuses sound better with tube amps vs. solid state. 😀 Quote Link to comment Share on other sites More sharing options...
henry4841 Posted December 12, 2020 Share Posted December 12, 2020 I never thought about fuses sounding better with SS or tubes. Possible I guess but I will venture to say negligible difference. There are drawbacks with using the thin wire fuses but I really have not had any problems using fuses. I do a lot of building and testing of audio equipment swapping them in and out of my system and would not use my speakers without fuses to protect them. Crap happens. Anyone just has to look inside drivers and speaker voice coils if one wants to see what tiny wires look like. Right now I am not using diodes on my AA's and even if I did not have fuses I probably would not. If the tweeters blow I would just buy a set of Crites tweeters and be done with it. That or either put a better tweeter in a box on top of my speakers. Using tweeters that are delicate is something from the past. Sure they sound good but progress has moved on since they were used. Better options are now available. One advantage of tweeter in a box on top is that one can position the tweeter in line with the other drivers. Improves phase differences. Quote Link to comment Share on other sites More sharing options...
jimjimbo Posted December 12, 2020 Share Posted December 12, 2020 16 minutes ago, henry4841 said: I never thought about fuses sounding better with SS or tubes. Possible I guess but I will venture to say negligible difference. I think Peter P. was just kidding..... 1 Quote Link to comment Share on other sites More sharing options...
henry4841 Posted December 12, 2020 Share Posted December 12, 2020 1 hour ago, jimjimbo said: I think Peter P. was just kidding..... Your probably right. Thinking to serious this morning. Quote Link to comment Share on other sites More sharing options...
DizRotus Posted December 12, 2020 Share Posted December 12, 2020 Unless you’re using a high power solid state amp on 11, it’s unlikely you will need protection for OEM tweeters. Skip the Zener diodes. Quote Link to comment Share on other sites More sharing options...
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