-13,8V (-39Vpp)
+34.5V (+97.6Vpp)
sqrt(216.2Vrms * 264.5Vrms)
= 239.134 Vrms
240Vac
everything revolves around 240Vac and that is exactly what I have been measuring in my hometown, very consistently throughout the day, for at least seven years. A few years ago, nobody here had a PV system, and at that time an estimated 90% of local pensioners, retirees and farmers denied climate change..!
By the way
and that brings us back to the topic: why don't MF & CEO publish anything about the rudimentary DC protection of the new A1 - and dear Jean-Paul, how did you know that there is DC insurance? Was that just a guess on your part?
I won't open the door to the Grim Reaper if he doesn't want to flatter me with at least an original Aleph-5 from Nelson Pass under his arm.
With JLH69 he has to wait outside until I've turned to dust.
😉
kind regards,
HBt.
Completely forgotten - and I have an "Eisenport".
😉
If anyone still has access to the original service documents for the current MF-A1, I would be grateful for a PM (or E-Mail). Everything is absolutely confidential so that no one has to worry about their job.
There are relays in the outputs. Those are to prevent the famous loud plops. When applying relays in a device with a burned woofer reputation it makes sense to apply the equally standard DC protection. Why omit one or the other when using relays anyway?
Both are standard in any japanese quality amplifier since the eighties often with the famous and still going strong uPC1237 IC that does both. Maybe not so in the DIY class A scene where farting amplifiers are highly cherished and muting or DC protection seem to be undesired novelties or luxury addons.
For non farting non woofer burning amplifiers:
https://www.unisonic.com.tw/uploadfiles/836/part_no_pdf/UPC1237.pdf
You are not a good reader regarding the mains voltage situation but all is good.
Both are standard in any japanese quality amplifier since the eighties often with the famous and still going strong uPC1237 IC that does both. Maybe not so in the DIY class A scene where farting amplifiers are highly cherished and muting or DC protection seem to be undesired novelties or luxury addons.
For non farting non woofer burning amplifiers:
https://www.unisonic.com.tw/uploadfiles/836/part_no_pdf/UPC1237.pdf
You are not a good reader regarding the mains voltage situation but all is good.
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I'am a very good reader - but it's fine for me too.
Let's shake hands
This point is not really important, is it?
I can't remember a single original A1 that didn't switch on and off absolutely quietly. All of them (under my hands) were free of any pops and plops - which is actually quite obvious, as the circuit is completely symmetrical compared to the rails. 4* 10mF charging caps do the rest.
So, now I unfortunately have no more time for our chat.
I wish you a nice weekend,
HBt.
Let's shake hands
This point is not really important, is it?
I can't remember a single original A1 that didn't switch on and off absolutely quietly. All of them (under my hands) were free of any pops and plops - which is actually quite obvious, as the circuit is completely symmetrical compared to the rails. 4* 10mF charging caps do the rest.
So, now I unfortunately have no more time for our chat.
I wish you a nice weekend,
HBt.
It is a feature of A1 and plops may or may not occur at power on/off or when the caps start to dry out unequally and laymen owners notice but wait for it to fail completely. The relays are to prevent 2 possible undesired nasty phenomenons. Like smoke alarms preventive function is only worthwhile and well understood when there is a possible fire.
Fact: A1 has cost many a woofer. Or 2. Often a shorted diode because of sick caps or the other way around.
Same here. Have a nice weekend.
Fact: A1 has cost many a woofer. Or 2. Often a shorted diode because of sick caps or the other way around.
Same here. Have a nice weekend.
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Please don't take this the wrong way:
but it would be great of you to open a supplementary post instead of the constant, retroactive editing - that distorts things to much.
but it would be great of you to open a supplementary post instead of the constant, retroactive editing - that distorts things to much.
I believe you 100% on this point. No matter what the error is - with an A1original it will end fatally for the LS.
Now
weekend !
greetings,
HBt.
Now
weekend !greetings,
HBt.
Don't panic, a quiet no would have been enough for me - I expected a no, but not a loud one.
Thank you for not taking the hint the wrong way. Apart from that, you obviously do what you want and what you think is right - regardless of what you do; it's fine for me.
Unrelated to the horrors of ultrabright blue leds but does anyone else remember Jimmy Hughes from HFNRR?
In the 80s Jimmy was disconnecting the lone led on amps for the perceived sonic improvement it brought. Today we use the same leds by the kilo as low noise voltage references🙂
In the 80s Jimmy was disconnecting the lone led on amps for the perceived sonic improvement it brought. Today we use the same leds by the kilo as low noise voltage references🙂
Was once in his flat in the Barbican and even then he had the largest collection of records I have seen.
It is not a large apartment and that visit was at least 30 years ago. I gather that since then he has continued to collect
and has taken a wife! There must be little room to stand up.
By the way he is an extremely nice guy who was then a camera technician working a lot on Sinars and the like.
Back to the Topic!
THD (without noise)
up to the ninth harmonic
Any Questions? The table shows my current determination in percent with the famous Keithley 2015 THD meter. Both channels driven!
| 100Hz | 1000Hz | 10000Hz |
0,5W | 0,005 | 0,012 | 0,001 |
1W | 0,003 | 0,018 | 0,009 |
5W | 0,045 | 0,071 | 0,066 |
10W | 0,142 | 0,169 | 0,165 |
15W | 0,216 | 0,244 | 0,243 |
20W | 0,321 | 0,348 | 0,311 |
up to the ninth harmonic
Any Questions? The table shows my current determination in percent with the famous Keithley 2015 THD meter. Both channels driven!
If the patents have expired I can't see a problem.The way I see it you can save a lot of money on amplification and what you save there you can spend on speakers and room treatments which are likely to give much better gains in overall sound.
And as far as upsetting the super high end makers/ marketers who have increased their prices to a ridiculous extent and by so doing made them unaffordable to all but the wealthy 1%-screw them!They get what they deserve.
Am I the only writer in this thread who has an original A1 on his desk?
Mains today 236Vrms,
HBt.
Mains today 236Vrms,
HBt.
A side note:
Between1.3kHz and 1.9kHz the internal components of the A1 sing a song! You can clearly hear the excitation frequency 🙁 .
#
The damping factor is still missing, i.e. a determination of the dynamic output impedance of the little sound wizard.
MF gives the damping factor as a value of 150 - and I simply don't believe that.
HBt.
(the EU agreement originally intended was: from 2015 eu wide 240Vac +/-5%; however, this did not happen, now we have the lazy transitional egg)
Between1.3kHz and 1.9kHz the internal components of the A1 sing a song! You can clearly hear the excitation frequency 🙁 .
#
The damping factor is still missing, i.e. a determination of the dynamic output impedance of the little sound wizard.
MF gives the damping factor as a value of 150 - and I simply don't believe that.
HBt.
(the EU agreement originally intended was: from 2015 eu wide 240Vac +/-5%; however, this did not happen, now we have the lazy transitional egg)