T
TheExperimenter
Guest
On 11/6/19 8:46 PM, Phil Allison wrote:
plonk
plonk
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B
bitrex
Guest
On 11/6/19 11:35 PM, Phil Allison wrote:
The hand-held variety are pretty much useless for any legit self-defense
purpose. Someone armed with a knife and the defender armed with one of
those and the defender is in a bad place, the guy with the knife is way
more dangerous.
They only have a few legitimate legal purposes for say law enforcement
to try to get compliance out of a prisoner who's combative but already
cuffed or otherwise disarmed/subdued.
Ralph Mowery wrote:
------------------
That 35 billion volts should be a tipoff the thing is a toy.
** "35 Billion" is the model number only.
Tasers are only around 50,000 volts
See demo:
https://www.youtube.com/watch?v=KZ2IDpiBKEQ
The thing is fairly harmless, in most cases.
The issue is few people KNOW that so can feel very threatened by one.
May be used to commit crimes like robbery, car jacking and worse.
Similar to a replica hand gun.
Why they are banned in so many places.
.... Phil
..... Phil
The hand-held variety are pretty much useless for any legit self-defense
purpose. Someone armed with a knife and the defender armed with one of
those and the defender is in a bad place, the guy with the knife is way
more dangerous.
They only have a few legitimate legal purposes for say law enforcement
to try to get compliance out of a prisoner who's combative but already
cuffed or otherwise disarmed/subdued.
P
Phil Allison
Guest
bitrex wrote:
----------------
** Everyone now knows the answer to a guy with a knife.
You carry a *BIGGER* knife !
Apologies to Paul Hogan ...
..... Phil
----------------
Someone armed with a knife and the defender armed with one of
those and the defender is in a bad place, the guy with the knife is way
more dangerous.
** Everyone now knows the answer to a guy with a knife.
You carry a *BIGGER* knife !
Apologies to Paul Hogan ...
..... Phil
Guest
On Wednesday, 6 November 2019 23:33:39 UTC, TheExperimenter wrote:
At least you admit you don't know why people were concerned. Obviously that does not mean the concerning issues don't exist.
NT
Ok, this post is for all the people making a big fuss when I asked about
stun gun components. I got ahold of one this week called VIPERTEK
I don't know what all the fuss was about. It's clear that these are
At least you admit you don't know why people were concerned. Obviously that does not mean the concerning issues don't exist.
NT
T
TheExperimenter
Guest
On 11/7/19 1:19 AM, tabbypurr@gmail.com wrote:
True. There is so much false advertising coming out of Chinese made
products that it is next to impossible to determine what is legitimate
and what isn't. Many of the parts I was asking about a while back now
have their origin in Chinese makers. Venders here (US) sell them under
the same part numbers and don't have a clue that the quality of the part
may be greatly compromised.
When you look at the schematic for the stun gun I was repairing versus
the one I was testing, with the latter being found online with enough
googling, the difference is like night and day. The little HV modules
like this Vipertek and the numerous others like it uses puts out roughly
20- 30 KV at the maximum at <20 watts. The electrodes are small and
smooth. Combine the weak HV and a bit of clothing will almost assuredly
mean not stopping hardly any attacker. Even the "higher power" units
being marketed have less than one inch sparks and again use the Chinese
modules. With the smooth electrodes and weak output, even those are
going to have a hard time stopping would be attackers.
On Wednesday, 6 November 2019 23:33:39 UTC, TheExperimenter wrote:
Ok, this post is for all the people making a big fuss when I asked about
stun gun components. I got ahold of one this week called VIPERTEK
I don't know what all the fuss was about. It's clear that these are
At least you admit you don't know why people were concerned. Obviously that does not mean the concerning issues don't exist.
NT
True. There is so much false advertising coming out of Chinese made
products that it is next to impossible to determine what is legitimate
and what isn't. Many of the parts I was asking about a while back now
have their origin in Chinese makers. Venders here (US) sell them under
the same part numbers and don't have a clue that the quality of the part
may be greatly compromised.
When you look at the schematic for the stun gun I was repairing versus
the one I was testing, with the latter being found online with enough
googling, the difference is like night and day. The little HV modules
like this Vipertek and the numerous others like it uses puts out roughly
20- 30 KV at the maximum at <20 watts. The electrodes are small and
smooth. Combine the weak HV and a bit of clothing will almost assuredly
mean not stopping hardly any attacker. Even the "higher power" units
being marketed have less than one inch sparks and again use the Chinese
modules. With the smooth electrodes and weak output, even those are
going to have a hard time stopping would be attackers.
B
bitrex
Guest
On 11/7/19 9:01 PM, Phil Allison wrote:
Related to some kind of distortion or effect box before the input, like
maybe one of those tube compressor/limiters that have a transformer
coupled output and put out a hot signal. Or running the guitar into a
mic preamp first and using similar output stage.
On Friday, November 8, 2019 at 12:57:25 PM UTC+11, bitrex wrote:
On 11/7/19 8:34 PM, Phil Allison wrote:
Hi to all my loyal followers,
-----------------------------
The term "bounce" is applied when an item that has been recently repaired is brought back for a similar or repeat failure.
Mostly it's a false alarm, a new problem or just once in a while the same failure involving the new parts. This is the worst scenario and for me very rare.
One that comes to mind was a MusicMan hybrid guitar amp - the RD50. The circuit is all solid state except for a pair of 6L6GC tubes for output.
https://www.thetubestore.com/lib/thetubestore/schematics/MusicMan/Musicman-RD50A-Schematic.pdf
One came to me with the input op-amp ( IC1) having it's output stuck to a DC rail. Fitted a new TL072 and away it went, good as new. Unusual failure, but shit happens sometimes.
It was back in a week with the new IC blown, just like before.
Another TL072 fixed it again, but I smelt a big fat rat.
Since the op-amp interfaced with the external world of musicians and their assorted paraphernalia - it must had failed due to abuse, twice.
But what exactly ? To stop the nonsense, I fitted 1N4148 diodes from pin 3 to each rail as a precaution. Walter C. Jung's "IC Op-Amp Cookbook " gave support for fact that such inputs were vulnerable.
The customer was not happy, he insisted on speaking with me and was very aggressive. I had understood he was a school teacher but it turned out he was in fact a *Taekwando* instructor !!
He expected the new repair to be covered by warranty, but I was not budging.
He insisted that guitar amps were built very tough to take all sorts of abuse.
I assured him he was mistaken: "I make my living because that's not true" - I stated firmly.
After extracting a few details from him, it all became clear.
Any guess what seemingly innocent act he had performed done, twice ?
--------------------
Question 2:
The same amp has a shameful design problem with the output stage.
Wilful stupidity.
Bet nobody gets it.
He was running line-level signal from a mixer into the input, had the
line out from the amp connected to the same mixer, and accidentally
routed the output directly to the input
** Very devious thinking there.
The actual scenario is quite simple and what many musos do all the time.
Guitarists that is ...
..... Phil
Related to some kind of distortion or effect box before the input, like
maybe one of those tube compressor/limiters that have a transformer
coupled output and put out a hot signal. Or running the guitar into a
mic preamp first and using similar output stage.
B
bitrex
Guest
On 11/7/19 8:34 PM, Phil Allison wrote:
He was running line-level signal from a mixer into the input, had the
line out from the amp connected to the same mixer, and accidentally
routed the output directly to the input
Hi to all my loyal followers,
-----------------------------
The term "bounce" is applied when an item that has been recently repaired is brought back for a similar or repeat failure.
Mostly it's a false alarm, a new problem or just once in a while the same failure involving the new parts. This is the worst scenario and for me very rare.
One that comes to mind was a MusicMan hybrid guitar amp - the RD50. The circuit is all solid state except for a pair of 6L6GC tubes for output.
https://www.thetubestore.com/lib/thetubestore/schematics/MusicMan/Musicman-RD50A-Schematic.pdf
One came to me with the input op-amp ( IC1) having it's output stuck to a DC rail. Fitted a new TL072 and away it went, good as new. Unusual failure, but shit happens sometimes.
It was back in a week with the new IC blown, just like before.
Another TL072 fixed it again, but I smelt a big fat rat.
Since the op-amp interfaced with the external world of musicians and their assorted paraphernalia - it must had failed due to abuse, twice.
But what exactly ? To stop the nonsense, I fitted 1N4148 diodes from pin 3 to each rail as a precaution. Walter C. Jung's "IC Op-Amp Cookbook " gave support for fact that such inputs were vulnerable.
The customer was not happy, he insisted on speaking with me and was very aggressive. I had understood he was a school teacher but it turned out he was in fact a *Taekwando* instructor !!
He expected the new repair to be covered by warranty, but I was not budging.
He insisted that guitar amps were built very tough to take all sorts of abuse.
I assured him he was mistaken: "I make my living because that's not true" - I stated firmly.
After extracting a few details from him, it all became clear.
Any guess what seemingly innocent act he had performed done, twice ?
--------------------
Question 2:
The same amp has a shameful design problem with the output stage.
Wilful stupidity.
Bet nobody gets it.
.... Phil
He was running line-level signal from a mixer into the input, had the
line out from the amp connected to the same mixer, and accidentally
routed the output directly to the input
P
Phil Allison
Guest
On Friday, November 8, 2019 at 12:57:25 PM UTC+11, bitrex wrote:
** Very devious thinking there.
The actual scenario is quite simple and what many musos do all the time.
Guitarists that is ...
...... Phil
On 11/7/19 8:34 PM, Phil Allison wrote:
Hi to all my loyal followers,
-----------------------------
The term "bounce" is applied when an item that has been recently repaired is brought back for a similar or repeat failure.
Mostly it's a false alarm, a new problem or just once in a while the same failure involving the new parts. This is the worst scenario and for me very rare.
One that comes to mind was a MusicMan hybrid guitar amp - the RD50. The circuit is all solid state except for a pair of 6L6GC tubes for output.
https://www.thetubestore.com/lib/thetubestore/schematics/MusicMan/Musicman-RD50A-Schematic.pdf
One came to me with the input op-amp ( IC1) having it's output stuck to a DC rail. Fitted a new TL072 and away it went, good as new. Unusual failure, but shit happens sometimes.
It was back in a week with the new IC blown, just like before.
Another TL072 fixed it again, but I smelt a big fat rat.
Since the op-amp interfaced with the external world of musicians and their assorted paraphernalia - it must had failed due to abuse, twice.
But what exactly ? To stop the nonsense, I fitted 1N4148 diodes from pin 3 to each rail as a precaution. Walter C. Jung's "IC Op-Amp Cookbook " gave support for fact that such inputs were vulnerable.
The customer was not happy, he insisted on speaking with me and was very aggressive. I had understood he was a school teacher but it turned out he was in fact a *Taekwando* instructor !!
He expected the new repair to be covered by warranty, but I was not budging.
He insisted that guitar amps were built very tough to take all sorts of abuse.
I assured him he was mistaken: "I make my living because that's not true" - I stated firmly.
After extracting a few details from him, it all became clear.
Any guess what seemingly innocent act he had performed done, twice ?
--------------------
Question 2:
The same amp has a shameful design problem with the output stage.
Wilful stupidity.
Bet nobody gets it.
He was running line-level signal from a mixer into the input, had the
line out from the amp connected to the same mixer, and accidentally
routed the output directly to the input
** Very devious thinking there.
The actual scenario is quite simple and what many musos do all the time.
Guitarists that is ...
...... Phil
P
Phil Allison
Guest
bitrex wrote:
-------------
** Normal use, no unusual devices and something he had done many times.
...... Phil
-------------
** Very devious thinking there.
The actual scenario is quite simple and what many musos do all the time.
Guitarists that is ...
..... Phil
Related to some kind of distortion or effect box before the input, like
maybe one of those tube compressor/limiters that have a transformer
coupled output and put out a hot signal. Or running the guitar into a
mic preamp first and using similar output stage.
** Normal use, no unusual devices and something he had done many times.
...... Phil
B
boB
Guest
On Thu, 7 Nov 2019 19:40:03 -0800 (PST), Phil Allison
<pallison49@gmail.com> wrote:
Smashed his guitar on the amp on stage of course trying to be Jimi
Hendrix
<pallison49@gmail.com> wrote:
bitrex wrote:
-------------
** Very devious thinking there.
The actual scenario is quite simple and what many musos do all the time.
Guitarists that is ...
..... Phil
Related to some kind of distortion or effect box before the input, like
maybe one of those tube compressor/limiters that have a transformer
coupled output and put out a hot signal. Or running the guitar into a
mic preamp first and using similar output stage.
** Normal use, no unusual devices and something he had done many times.
..... Phil
Smashed his guitar on the amp on stage of course trying to be Jimi
Hendrix
P
Phil Allison
Guest
boB wrote:
------------
** Might have felt like hitting me with his guitar though.
When I explained it was a very clear case of input overload damage that I had done a mod to prevent in future, he asked rudely:
" Why didn't you do the mod the first time ? "
As if.
...... Phil
...... Phil
------------
** Normal use, no unusual devices and something he had done many times.
Smashed his guitar on the amp on stage of course trying to be Jimi
Hendrix
** Might have felt like hitting me with his guitar though.
When I explained it was a very clear case of input overload damage that I had done a mod to prevent in future, he asked rudely:
" Why didn't you do the mod the first time ? "
As if.
...... Phil
...... Phil
J
Jeff Layman
Guest
On 08/11/19 01:34, Phil Allison wrote:
Bit strange - you say the circuit is all solid state except for the
6L6GC output tubes. But the schematic shows a 12AX7 is used too (V1).
What is odd is that the pin-outs at the bottom right of the diagram show
only the 6L6GC base connections. The 12AX7 base connections aren't
mentioned. Probably just a simple omission.
--
Jeff
Hi to all my loyal followers,
-----------------------------
The term "bounce" is applied when an item that has been recently repaired is brought back for a similar or repeat failure.
Mostly it's a false alarm, a new problem or just once in a while the same failure involving the new parts. This is the worst scenario and for me very rare.
One that comes to mind was a MusicMan hybrid guitar amp - the RD50. The circuit is all solid state except for a pair of 6L6GC tubes for output.
https://www.thetubestore.com/lib/thetubestore/schematics/MusicMan/Musicman-RD50A-Schematic.pdf
Bit strange - you say the circuit is all solid state except for the
6L6GC output tubes. But the schematic shows a 12AX7 is used too (V1).
What is odd is that the pin-outs at the bottom right of the diagram show
only the 6L6GC base connections. The 12AX7 base connections aren't
mentioned. Probably just a simple omission.
--
Jeff
A
Arie de Muynck
Guest
On 2019-11-08 02:34, Phil Allison wrote:
Some remarks, not necessarily what you were looking for:
Pulling both speaker outputs leaves no line out signal.
Running with open output may cause 6L6 internal flash over. If that
reaches g1, Q3/Q4 will suffer.
The 75K/680E dividers before Q3/A4 may not bias them properly into class
AB. It depends on the 6L6 characteristics.
The D16,D17 diodes will lower the max reverse Vbe but hardly to a safe
value. And they overload the TL072, shifting it's operation point
causing distortion. Maybe a selling point for guitar amps...
Arie
https://www.thetubestore.com/lib/thetubestore/schematics/MusicMan/Musicman-RD50A-Schematic.pdf
Question 2:
The same amp has a shameful design problem with the output stage.
Wilful stupidity.
Bet nobody gets it.
Some remarks, not necessarily what you were looking for:
Pulling both speaker outputs leaves no line out signal.
Running with open output may cause 6L6 internal flash over. If that
reaches g1, Q3/Q4 will suffer.
The 75K/680E dividers before Q3/A4 may not bias them properly into class
AB. It depends on the 6L6 characteristics.
The D16,D17 diodes will lower the max reverse Vbe but hardly to a safe
value. And they overload the TL072, shifting it's operation point
causing distortion. Maybe a selling point for guitar amps...
Arie
T
TTman
Guest
On 08/11/2019 01:34, Phil Allison wrote:
Hi to all my loyal followers,
-----------------------------
The term "bounce" is applied when an item that has been recently repaired is brought back for a similar or repeat failure.
Mostly it's a false alarm, a new problem or just once in a while the same failure involving the new parts. This is the worst scenario and for me very rare.
One that comes to mind was a MusicMan hybrid guitar amp - the RD50. The circuit is all solid state except for a pair of 6L6GC tubes for output.
https://www.thetubestore.com/lib/thetubestore/schematics/MusicMan/Musicman-RD50A-Schematic.pdf
One came to me with the input op-amp ( IC1) having it's output stuck to a DC rail. Fitted a new TL072 and away it went, good as new. Unusual failure, but shit happens sometimes.
It was back in a week with the new IC blown, just like before.
Another TL072 fixed it again, but I smelt a big fat rat.
Since the op-amp interfaced with the external world of musicians and their assorted paraphernalia - it must had failed due to abuse, twice.
But what exactly ? To stop the nonsense, I fitted 1N4148 diodes from pin 3 to each rail as a precaution. Walter C. Jung's "IC Op-Amp Cookbook " gave support for fact that such inputs were vulnerable.
The customer was not happy, he insisted on speaking with me and was very aggressive. I had understood he was a school teacher but it turned out he was in fact a *Taekwando* instructor !!
He expected the new repair to be covered by warranty, but I was not budging.
He insisted that guitar amps were built very tough to take all sorts of abuse.
I assured him he was mistaken: "I make my living because that's not true" - I stated firmly.
After extracting a few details from him, it all became clear.
Any guess what seemingly innocent act he had performed done, twice ?
--------------------
Question 2:
The same amp has a shameful design problem with the output stage.
Wilful stupidity.
Bet nobody gets it.
.... Phil
I hope you tell us the answers later...
P
Phil Allison
Guest
Arie de Muynck wrote:
------------------------
Phil Allison wrote:
** Of course, it's not safe to run a tube amp with no load.
> Running with open output may cause 6L6 internal flash over.
** Can be fatal for any tube amp.
** Q3 & Q4 are special selected devices from Motorola.
SJE = special type.
Bias is within limits with them installed.
D16 and D17 temp compensate the bias.
** No, Q3 & Q4 have low input impedances due to NFB.
The TL072 cannot produce more than sufficient drive.
** Not before the 6L6 tubes are square waving.
You are miles off.
...... Phil
------------------------
Phil Allison wrote:
https://www.thetubestore.com/lib/thetubestore/schematics/MusicMan/Musicman-RD50A-Schematic.pdf
Question 2:
The same amp has a shameful design problem with the output stage.
Wilful stupidity.
Bet nobody gets it.
Some remarks, not necessarily what you were looking for:
Pulling both speaker outputs leaves no line out signal.
** Of course, it's not safe to run a tube amp with no load.
> Running with open output may cause 6L6 internal flash over.
** Can be fatal for any tube amp.
The 75K/680E dividers before Q3/A4 may not bias them properly into class
AB. It depends on the 6L6 characteristics.
** Q3 & Q4 are special selected devices from Motorola.
SJE = special type.
Bias is within limits with them installed.
D16 and D17 temp compensate the bias.
The D16,D17 diodes will lower the max reverse Vbe but hardly to a safe
value.
** No, Q3 & Q4 have low input impedances due to NFB.
The TL072 cannot produce more than sufficient drive.
And they overload the TL072,
** Not before the 6L6 tubes are square waving.
You are miles off.
...... Phil
M
Michael Terrell
Guest
On Friday, November 8, 2019 at 7:13:15 AM UTC-5, Phil Allison wrote:
No, it isn't The 'S' prefix is how Motorola marked house numbered parts for customers. Motorola quit making transistors, two decades ago. They may or may not have been screened at the factory. There are several reasons for House Numbering. One is to reduce employee theft, and another is to prevent warranty fraud.
Their Semiconductor products were spun off into ON Semiconductor in 1999.
In another thread you made a comment about ';an old HP Curve Tracer. They never built any for sale. If you do some research they built one and only one for use in house by one engineer. Only one unit. It wasn't until they became Agilent that they started producing equipment to test semiconductors on the production line.
SJE = special type.
No, it isn't The 'S' prefix is how Motorola marked house numbered parts for customers. Motorola quit making transistors, two decades ago. They may or may not have been screened at the factory. There are several reasons for House Numbering. One is to reduce employee theft, and another is to prevent warranty fraud.
Their Semiconductor products were spun off into ON Semiconductor in 1999.
In another thread you made a comment about ';an old HP Curve Tracer. They never built any for sale. If you do some research they built one and only one for use in house by one engineer. Only one unit. It wasn't until they became Agilent that they started producing equipment to test semiconductors on the production line.
P
Phil Allison
Guest
Clive Arthur wrote:
-----------------
Phil Allison wrote:
** Not the cause
You have to what made the TL072 fail.
..... Phil
-----------------
Phil Allison wrote:
Any guess what seemingly innocent act he had performed done, twice ?
Played 'loud' with the amp turned off.
** Not the cause
You have to what made the TL072 fail.
..... Phil
C
Clive Arthur
Guest
On 08/11/2019 01:34, Phil Allison wrote:
<snip>
> Any guess what seemingly innocent act he had performed done, twice ?
Played 'loud' with the amp turned off.
Cheers
--
Clive
Hi to all my loyal followers,
<snip>
> Any guess what seemingly innocent act he had performed done, twice ?
Played 'loud' with the amp turned off.
Cheers
--
Clive
P
Phil Allison
Guest
Michael Terrell is an asshole wrote:
-----------------------------------
** Yes it is.
> The 'S' prefix is how Motorola marked house numbered parts for customers.
** Yep, after putting them through a selection process as needed for a particular purpose. The stock number in this case was quite obscure.
> Motorola quit making transistors, two decades ago.
** The amp is a 40 years old design, as marked on the schem.
SJE1692s were matched for close tolerance on Vbe and Hfe.
All examples were damn near the the same.
** Was not mine and I never saw the damn thing.
Could have been Tek575 or 576, not HP.
So fucking what?
...... Phil
-----------------------------------
Phil Allison wrote:
SJE = special type.
No, it isn't
** Yes it is.
> The 'S' prefix is how Motorola marked house numbered parts for customers.
** Yep, after putting them through a selection process as needed for a particular purpose. The stock number in this case was quite obscure.
> Motorola quit making transistors, two decades ago.
** The amp is a 40 years old design, as marked on the schem.
SJE1692s were matched for close tolerance on Vbe and Hfe.
All examples were damn near the the same.
In another thread you made a comment about ';an old HP Curve Tracer.
** Was not mine and I never saw the damn thing.
Could have been Tek575 or 576, not HP.
So fucking what?
...... Phil
Guest
On Friday, 8 November 2019 12:37:27 UTC, Michael Terrell wrote:
> In another thread you made a comment about ';an old HP Curve Tracer. They never built any for sale. If you do some research they built one and only one for use in house by one engineer. Only one unit. It wasn't until they became Agilent that they started producing equipment to test semiconductors on the production line.
I used to have a Marconi badged sig gen that Marconi never made. It turned out to be some other mfr they had rebadged, then their evaluation rejected. It was afaik a 1 off.
NT
> In another thread you made a comment about ';an old HP Curve Tracer. They never built any for sale. If you do some research they built one and only one for use in house by one engineer. Only one unit. It wasn't until they became Agilent that they started producing equipment to test semiconductors on the production line.
I used to have a Marconi badged sig gen that Marconi never made. It turned out to be some other mfr they had rebadged, then their evaluation rejected. It was afaik a 1 off.
NT