Topic: m148 Problem :(

[Chuck]

I re-read my post and want to correct it by saying, measure the voltage across PINS 1 & 2 on the microphone side, not the m148 output. What you will be doing is measuring the total voltage of the batteries. If the voltage is low, the batteries are the problem.

Let us know what you find out.

Chuck

[terrapinj]

That's probably not a bad idea Chuck. +T for the advice.

Let me know what you guys think about this. I guess I kind of forgot to mention this. As a matter of fact I forgot until I talked to Doug this morning. When the levels dropped I turned the gain knob about from maybe 4 to 5 and the levels went somewhat back to normal. That kind of sounds like something with the 671 but I'm not sure. Doug was saying that the person that had a similar problem had something go wrong with the contact points or something like that with the gain knob. I'll do some tests and let you guys know what I find.

Harrison

i don't know if that would be conclusive either way. you could have just as easily added enough gain with the 671 to correct for the drop from the m148(if thats the problem). the fact that the drop happens towards the end of the show each time is what made me think it was battery related, but it could be a coincidence as well.

how much gain are you generally adding with the 671? sounded like your levels were dropping ~10db or so are you even adding this much gain with the 671?

[Dutchman1101]

That's probably not a bad idea Chuck. +T for the advice.

Let me know what you guys think about this. I guess I kind of forgot to mention this. As a matter of fact I forgot until I talked to Doug this morning. When the levels dropped I turned the gain knob about from maybe 4 to 5 and the levels went somewhat back to normal. That kind of sounds like something with the 671 but I'm not sure. Doug was saying that the person that had a similar problem had something go wrong with the contact points or something like that with the gain knob. I'll do some tests and let you guys know what I find.

Harrison

i don't know if that would be conclusive either way. you could have just as easily added enough gain with the 671 to correct for the drop from the m148(if thats the problem). the fact that the drop happens towards the end of the show each time is what made me think it was battery related, but it could be a coincidence as well.

how much gain are you generally adding with the 671? sounded like your levels were dropping ~10db or so are you even adding this much gain with the 671?

Well looking back to get the levels back somewhat to normal I really did not add that much gain. Like I said I went from 4 to 5 maybe 5 1/2 on the wheel. The levels were peaking at 12db on the 671 and when I adjusted the gain knob they went back to peaking at around 1 to 2 db. I haven’t had the 671 that long but I don’t think adjusting it 1 to 1 1/2 notches on the wheel should add that much gain causing me to believe now there might be something wrong with the 671. I'll keep you guys posted. I'm going to get a voltmeter tonight I think just to make sure.

Harrison

[sygdwm]

fwiw, the knob doesnt add gain it is an attenuator. i think.

[Dutchman1101]

fwiw, the knob doesnt add gain it is an attenuator. i think.

You are correct. I was using the wrong lingo I guess.

[Chuck]

http://www.sears.com/sr/javasr/subcat.do?BV_SessionID=@@@@1244533927.1172516711@@@@&BV_EngineID=cccjaddkfdlfhlecefecemldffidfjg.0&vertical=TOOL&cat=Electrical+Shop&subcat=Multi-Meters%2C+Testers+%26+Accessories

I searched Sears and mulitmeter and found one on sale for $13. If you have a Sears close, the digital one on top should do you just fine.

[Dutchman1101]

http://www.sears.com/sr/javasr/subcat.do?BV_SessionID=@@@@1244533927.1172516711@@@@&BV_EngineID=cccjaddkfdlfhlecefecemldffidfjg.0&vertical=TOOL&cat=Electrical+Shop&subcat=Multi-Meters%2C+Testers+%26+Accessories

I searched Sears and mulitmeter and found one on sale for $13. If you have a Sears close, the digital one on top should do you just fine.

Thanks Chuck! I do have a Sears fairly close by. I think I'll do that. I'll pick up a set of RCA's and do some tests tonight.

[THE NIZ BIAAAAACH!]

Yo, you can replace the batteries your self really easy.  If you need help come up her to breck one day and I'll help, or we can wire it for an external.

Edit: Can you wire them to take external power? I've never heard of that. I dont see why not

I've never heard of being able to do this.  The only drawback I could see is that Doug used these batteries for their low noise, correct?  So using a lion or similar may introduce some unwanted noise?

If you remove the internal battery, and wire the battery output to the charger input, you then have an external solution.  All this does is make the external charger input into a terminal for what ever battery you want to hook up.  Add the same size conector as your charger and your ready to go.

[sygdwm]

Yo, you can replace the batteries your self really easy.  If you need help come up her to breck one day and I'll help, or we can wire it for an external.

Edit: Can you wire them to take external power? I've never heard of that. I dont see why not

I've never heard of being able to do this.  The only drawback I could see is that Doug used these batteries for their low noise, correct?  So using a lion or similar may introduce some unwanted noise?

If you remove the internal battery, and wire the battery output to the charger input, you then have an external solution.  All this does is make the external charger input into a terminal for what ever battery you want to hook up.  Add the same size conector as your charger and your ready to go.

you make that sound WAY easier than it probably is. first, there are 8 batts in there. also, what kind of battery would give you 48v externally?

/devils advovate

[THE NIZ BIAAAAACH!]

Well, there are lion packs made that do supply 48v, also when batteries are wired in series the voltage is added, so in this way you could wire 4, 12v cells in seris to reach 48v, or any derivative of these numbers.  Of course you would not need to use huge cells, just many small ones.

[Chuck]

I have thought making a phantom power supply using (5) 9.6 v NiMH batteries. I talked to Doug about it and he said the lead was better, but if you built it right, the NiMH would be good also.

[sygdwm]

so, even if it could be done, it would probably screw with the sound and/or noise floor.

/sucks as i gaze at a dead m148 waiting for new sla's that have been on backorder for 2 weeks. 

[THE NIZ BIAAAAACH!]

It can be done and if the battery provides consistent voltage"clean power" it sould be just fine.

[Dutchman1101]

I sent you a PM Chuck.

[Chuck]

I sent you a PM Chuck.

I am trying to respond, but I am having problems with the site, or possibly my internet connection this morning...