Edgeivi Posted June 12, 2023 Share Posted June 12, 2023 Hey all, I recently purchased a set of Belles and I just finished recapping and did my first extended listening session with them using an older decware triode amp SE84CS(listening loud) when my amp just shut down from overheating. I tried my Jolida 102b amp and same result. I’m guessing that the speakers have a higher load on the amp causing more heat,? but since I also just recapped them I’m not sure (it’s my first recap job too). This is my first big pair of speakers and my amps work fine with my fortes. So the question to you all is this normal for Belles or La Scalas to push little amps or should I be looking at my solder joints on the crossover for a botched solder joint? Quote Link to comment Share on other sites More sharing options...
Peter P. Posted June 12, 2023 Share Posted June 12, 2023 What's the rated output of the amp, into what the manufacturer's spec'd speaker impedance? I.E., are they "X" watts into an 8 ohm load, 4 ohm load, etc.? What's the rated impedance of your Belles? What do they measure when you stick a voltmeter on them? (I know you'll measure resistance and not impedance, but it's better than nothing.) How loud are you playing them? Quote Link to comment Share on other sites More sharing options...
winglet Posted June 12, 2023 Share Posted June 12, 2023 If the amps work fine with the forte, I’d suspect the Belle networks. Especially with the recent recap. Did the belle work good before the recap? Post a couple pics of the networks. What is the resistance measurement of each of the belle? Multimeter on the speaker input terminals.. Quote Link to comment Share on other sites More sharing options...
Edgeivi Posted June 12, 2023 Author Share Posted June 12, 2023 Both amps are el84 based tube amps. Decware is 2 watts, and the Jolida is 15 watts (I think) both for 8ohms. As far as I could tell they worked prior to recap but I didn’t listen to them for more than an hour and I didn’t push the volume. These are the resistance measurements for the speakers. 637 Woofer - 3.3 Squawker- 10.9 Tweeter - 6.5 Speaker Terminal - 3.6 638 Woofer - 3.3 Squawker- 10.5 Tweeter - 6.5 Speaker Terminal - 3.6 Pictures of the network’s will have to wait till after work. Quote Link to comment Share on other sites More sharing options...
Edgeivi Posted June 13, 2023 Author Share Posted June 13, 2023 Here’s one speakers crossover IMG_8292.heic Quote Link to comment Share on other sites More sharing options...
Edgeivi Posted June 13, 2023 Author Share Posted June 13, 2023 Here’s the other. They are AA crossovers. IMG_8291.heic Quote Link to comment Share on other sites More sharing options...
winglet Posted June 13, 2023 Share Posted June 13, 2023 Do either of those amps have 4 or 6 ohm taps to connect the speakers to? Quote Link to comment Share on other sites More sharing options...
henry4841 Posted June 13, 2023 Share Posted June 13, 2023 The Zen Decware is an SET and volume level should not shut the amp down because it is being run in class A and in class A the tubes are typically run at 80% no matter the volume. I suppose there could be problem if the secondary of the OPT's have too low an impendence but have never heard of it being problem before. No experience with the Jolida but guessing PP A/B and could be made to run too hot but seriously with our speakers you hearing would be damaged at too high a volume before the amp shut down. Most heritage speakers only use a couple of watts in a home setting. First thoughts, something not wired correctly. 1 Quote Link to comment Share on other sites More sharing options...
Marvel Posted June 14, 2023 Share Posted June 14, 2023 I never had any trouble driving my LS to a far-to-loud volume using my 2A3 amps, with 3.5 watts. I'm thinking you have something going on with the reworked crossovers, if both amps are having trouble. Quote Link to comment Share on other sites More sharing options...
Marvel Posted June 14, 2023 Share Posted June 14, 2023 Here's you pic... Quote Link to comment Share on other sites More sharing options...
mboxler Posted June 14, 2023 Share Posted June 14, 2023 On 6/11/2023 at 11:51 PM, Edgeivi said: ...should I be looking at my solder joints on the crossover for a botched solder joint? Yes. For example, if the last capacitor in the tweeter circuit is not properly connected, you will end up with a dead short around 7500hz. 1 Quote Link to comment Share on other sites More sharing options...
Edgeivi Posted June 14, 2023 Author Share Posted June 14, 2023 Sounds like the consensus is to check the solder joints. Thanks for the input all. Quote Link to comment Share on other sites More sharing options...
OO1 Posted June 14, 2023 Share Posted June 14, 2023 if all fails , re-install the old klipsch capacitors or buy new klipsch original capacitors Quote Link to comment Share on other sites More sharing options...
KT88 Posted June 15, 2023 Share Posted June 15, 2023 Apart from this specific case, what can generally make overheating caused by the load of the speaker output of a tube amplifier? I have not heard of this phenomenon. Would a short circuit or a too low impedance of a speaker cause this? Quote Link to comment Share on other sites More sharing options...
Marvel Posted June 15, 2023 Share Posted June 15, 2023 Sorry, I skipped reposting one of the crossover pics... Quote Link to comment Share on other sites More sharing options...
Peter P. Posted June 16, 2023 Share Posted June 16, 2023 23 hours ago, KT88 said: Apart from this specific case, what can generally make overheating caused by the load of the speaker output of a tube amplifier? I have not heard of this phenomenon. Would a short circuit or a too low impedance of a speaker cause this? Yes. When the impedance is too low for the amplifier's design, the speaker is drawing more current than the amp can deliver. Think of it like a water supply; if the reservoir can refill as fast as people are using the water for showers, laundry, etc., then there's no problem. But there IS a problem is the demand for water exceeds the rate at which the reservoir can refill from rain, snowmelt, whatever.The amp strains under the demand of the speaker, and heat builds up. If this "load" isn't reduced, the speaker may have built-in protection circuits and shut down. An amp's specs will usually tell you whether it is "rated" to deliver X watts into a Y ohm load. Some amps, even like my solid state amp, have a switch I set to match the impedance rating of the speakers. Believe it or not, you can actually put a volt meter, in current mode, on one of the speaker leads and measure the current draw. 1 Quote Link to comment Share on other sites More sharing options...
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