With my lack of knowledge I want to be careful with voltages. For a start I will connect series bulb on primary again then remove the amp module and place some load(?) after PS rectification and filter ? A small value fuse on secondary wires ? Just to check if current can be measured. If OK then will again connect amp modules. Dont know.
Also I was thinking about earlier varying current measurements, I guess probably since Wires were wrapped around multimeter probe with crocodile pin. I think loose contact there or at PS may be causing fluctuation.
Will update soon.
Thanks and Merry Christmas in advance.
Also I was thinking about earlier varying current measurements, I guess probably since Wires were wrapped around multimeter probe with crocodile pin. I think loose contact there or at PS may be causing fluctuation.
Will update soon.
Thanks and Merry Christmas in advance.
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Got little impatient and measured right away. So far no smoke, bangs or bursts. Amp is working fine. Power supply is as picture attached. 18-0-18V to 6A4 Rectifier to four 4700uf Capacitors. Series test bulb in place.
Volume adjusted to get 1V of Test Signal at speaker terminal on all measurements.
1) at Green dots centertap after rectification and filter I am getting 11.72A on multimeter dial at 20A AC setting . Probes on mA Setting.
2) at Blue dots +Ve rail after rectification and filter I am getting 9.4A on multimeter dial at 20A DC setting. Probes on mA Setting.
3) At 18V wire of secondary shown in Red dots. I am getting 9A on 20A MM AC setting. No current on DC setting even after switching MM probes .
What if my un branded speakers (Only 8ohms20W written onit) are actually low ohms. And because of that it is showing these currents ?
Volume adjusted to get 1V of Test Signal at speaker terminal on all measurements.
1) at Green dots centertap after rectification and filter I am getting 11.72A on multimeter dial at 20A AC setting . Probes on mA Setting.
2) at Blue dots +Ve rail after rectification and filter I am getting 9.4A on multimeter dial at 20A DC setting. Probes on mA Setting.
3) At 18V wire of secondary shown in Red dots. I am getting 9A on 20A MM AC setting. No current on DC setting even after switching MM probes .
What if my un branded speakers (Only 8ohms20W written onit) are actually low ohms. And because of that it is showing these currents ?
Attachments
Your readings seem odd tbh. I don't understand the bit about 'probe on milliamps setting'.
There is something strange with your readings. You can not be pulling those kind of currents , the numbers and what is happening don't compute. 18 volt winding, that gives 25 volt rails. 11 A at those kind of voltages is much heat and destruction and that obviously isn't happening. The bulb could not support those powers in any case.
So something seems wrong with the measurements.
There is something strange with your readings. You can not be pulling those kind of currents , the numbers and what is happening don't compute. 18 volt winding, that gives 25 volt rails. 11 A at those kind of voltages is much heat and destruction and that obviously isn't happening. The bulb could not support those powers in any case.
So something seems wrong with the measurements.
Oops. Pardon me. I think I got it. in a hurry Multimeter must have been set wrong way. Please ignore the post #1362. Sorry about that. Will test again.
Regards.
Regards.
If your multimeter is set to 20A, the probes should be on the A or 20A setting, not mA. Most multimeters differentiate the low and high current because of the fuse.
newbie + unknown tests + Basic equipments = embrassement 😱
So to save more embrassement I have recorded test results. here is video.
test - YouTube
Tested at Red dots of the picture. Test signal adjusted to get 1V at speaker terminal which I normally listen to. As you can see in the video Red multimeter Probe is on mA and Selection knob(dial) on 200mA setting. When no singal it showed around 38 (?) and with signal started it showed 68 (mA?)
So to save more embrassement I have recorded test results. here is video.
test - YouTube
Tested at Red dots of the picture. Test signal adjusted to get 1V at speaker terminal which I normally listen to. As you can see in the video Red multimeter Probe is on mA and Selection knob(dial) on 200mA setting. When no singal it showed around 38 (?) and with signal started it showed 68 (mA?)
Attachments
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Ah, the things that happen while I sleep. 🙂
That's looking better. Now I understand what you mean by probes on milliamp setting. They are plugged into the mA sockets, but you used the 20A scale. That would explain a lot. 38 and 68 mA makes much more sense.
That's looking better. Now I understand what you mean by probes on milliamp setting. They are plugged into the mA sockets, but you used the 20A scale. That would explain a lot. 38 and 68 mA makes much more sense.
phew! thats a relief. You dont know how hard it is to ask basic queries to professionals. Thank all you gentlemen. 🙂
here are more (probably useless) measurements. I measured test signal at 1v, 2v, 3v,4v. At Transformer Secondary (18v) lead as shown in previous picture.
1v=66mA
2v=100mA
3v=140mA
4v=184mA
4V is insane volume level considering I was happy at 1V. But Shall I draw conclusion that 3A rectifier discrete 4 diodes or a bridge rectifier package will be suffecient ? I am reluctant to use fast switching diodes. Any recommendations of normal soft recovery diodes/Bridge rectifier like KBPC type ? (Because my PS supply board has KBPC type holes.)
One more measurement for Actual Music. I played Direstraits (Calling Elvis) same volume setting level (4V) on test speaker and current draw at same points of secondary transformer flctuated from 60mA (normal passages) to around 150/160mA on loud drums. I guess MM cant show such quick transients so on safe side I will presume current draw on loud passage can be double.
thanks again
here are more (probably useless) measurements. I measured test signal at 1v, 2v, 3v,4v. At Transformer Secondary (18v) lead as shown in previous picture.
1v=66mA
2v=100mA
3v=140mA
4v=184mA
4V is insane volume level considering I was happy at 1V. But Shall I draw conclusion that 3A rectifier discrete 4 diodes or a bridge rectifier package will be suffecient ? I am reluctant to use fast switching diodes. Any recommendations of normal soft recovery diodes/Bridge rectifier like KBPC type ? (Because my PS supply board has KBPC type holes.)
One more measurement for Actual Music. I played Direstraits (Calling Elvis) same volume setting level (4V) on test speaker and current draw at same points of secondary transformer flctuated from 60mA (normal passages) to around 150/160mA on loud drums. I guess MM cant show such quick transients so on safe side I will presume current draw on loud passage can be double.
thanks again
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I'm glad you got it sorted out. Your questions are best suited to a new thread over in the amplifier section. Your readings for the loud 4V can serve as your max current draw.
Voted today @ 7 v
I was surprised that I required 7 v Jennifer Warner’s was quite loud, added the extra 2 dB and maybe 1 more . It does hold true though Bryston 2B and Spectral DMA 50 are my strongest amps. Don’t think I’ve ever clipped them significantly.
Using the B1K and on the other end ProAc Response 2s.Thanks for the thread, that was interesting.
Should have mentioned I used the 120 Hz file, I will use the higher frequencies and see what I get.
I was surprised that I required 7 v Jennifer Warner’s was quite loud, added the extra 2 dB and maybe 1 more . It does hold true though Bryston 2B and Spectral DMA 50 are my strongest amps. Don’t think I’ve ever clipped them significantly.
Using the B1K and on the other end ProAc Response 2s.Thanks for the thread, that was interesting.
Should have mentioned I used the 120 Hz file, I will use the higher frequencies and see what I get.
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I just finished performing the test.
I set my computer volume to max and ran the test tone from the audio output to one set of inputs in my A/V receiver with the volume set to the level I listen to TV.
I measured 0.133Vrms at the input to the Klipsch Hersey speaker.
I only tested with the 220Hz tone.
I measured 55dB Fast C weighted with a RS 33-2055 1M in front of the speaker.
I set my computer volume to max and ran the test tone from the audio output to one set of inputs in my A/V receiver with the volume set to the level I listen to TV.
I measured 0.133Vrms at the input to the Klipsch Hersey speaker.
I only tested with the 220Hz tone.
I measured 55dB Fast C weighted with a RS 33-2055 1M in front of the speaker.
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Thanks for the report. Your voltage and SPL seem odd. 55dB is low, I would expect somewhere near 66dB from the Hersey at 0.133V. Maybe I can make a calibrated pink noise file for you.
I will be glad to give it a try.
just realized I had left the A/V receiver in surround mode and most of the sound was coming from the center speaker. Switched to true stereo and got:
0.133Vrms
66 dB Fast C weighted 1M in front of the speaker on axis with the 12" driver. These are Heresy speakers from 1977, not the later series II or III.
just realized I had left the A/V receiver in surround mode and most of the sound was coming from the center speaker. Switched to true stereo and got:
0.133Vrms
66 dB Fast C weighted 1M in front of the speaker on axis with the 12" driver. These are Heresy speakers from 1977, not the later series II or III.
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Ah ha, thanks. That matches better what I would expect. One more step is you a willing:
Play back music from your computer and set it as loud as you normally would. Try to use music with a large dynamic range, like classical of modern recordings of Big Band.
Pop music and the radio have very limited dynamic range, so your volume control isn't turned up as high for loud levels. More dynamic recordings need to be turned up to get overall loud, then the peaks will be very high.
Play back music from your computer and set it as loud as you normally would. Try to use music with a large dynamic range, like classical of modern recordings of Big Band.
Pop music and the radio have very limited dynamic range, so your volume control isn't turned up as high for loud levels. More dynamic recordings need to be turned up to get overall loud, then the peaks will be very high.
I played a variety of of music I had digitized from records, all made prior to 1985 before the loudness wars began. These included Fleetwood Mack, Billy Joel, Jimmy Buffet Genesis, Deep Purple, James Taylor, Nazareth and a few others. I found a level I would normally play while working on projects, or upstairs cooking listening to the other system (also Heresy speakers).
I set the volume to what I would normally listen to at what I consider a moderate level.
Without hearing aids:
Speaker 0.712Vrms
1M in front of driver 73 dB
Listening position with music playing 60dB peak
With Hearing Aids:
Speaker 0.227Vrms
1M in front of driver 64 dB
Listening position with music playing 54dB peak
I set the volume to what I would normally listen to at what I consider a moderate level.
Without hearing aids:
Speaker 0.712Vrms
1M in front of driver 73 dB
Listening position with music playing 60dB peak
With Hearing Aids:
Speaker 0.227Vrms
1M in front of driver 64 dB
Listening position with music playing 54dB peak