Grainger Firebird 100H guitar amp, 2007

N

N_Cook

Guest
Anyone know anything about this company?
RoHS and tick N222 stickers on the back and and so the problem is the usual
for that .
But unusually the phrasing with it is "Made in P.R. China". Bought by the
owner from new. The idents on the overlays on the pcbs have been scratched
off. The paper label over the Asic/Pic on the digital board has been
scratched off. Also on that daughter board SMD IC with bogus Philips logo.
Badly done re-work on traces to a 15V regulator at some point.
Seconds/failed-test boards coming through a back-door from ,say, Peavey
production line and sold on ?
 
Epiphone would seem to be the origin, this one
http://farm4.static.flickr.com/3394/3498767796_d7fd8a6e4d.jpg
off page
http://retrorides.proboards.com/index.cgi?board=othrmod&action=print&thread=
59785

the red one , with change of name-plate on the front.
anyone know the Epiphone model number of that one ?
 
"Nutcase Kook "

got there in the end, Epiphone Triggerman 100H
Click to expand...

** What is in a name ?

A polished turd would still smell as foul, by any other name ...


( apologies to Willy Boy )


..... Phil
 
"N_Cook" <diverse@tcp.co.uk> wrote in message
news:jsmb6t$7f3$2@dont-email.me...
Anyone know anything about this company?
RoHS and tick N222 stickers on the back and and so the problem is the
usual
for that .
But unusually the phrasing with it is "Made in P.R. China". Bought by the
owner from new. The idents on the overlays on the pcbs have been scratched
off. The paper label over the Asic/Pic on the digital board has been
scratched off. Also on that daughter board SMD IC with bogus Philips logo.
Badly done re-work on traces to a 15V regulator at some point.
Seconds/failed-test boards coming through a back-door from ,say, Peavey
production line and sold on ?
Click to expand...

Grainger were amps that the now defunt Sound Contol had made in China. They
apparently came off the same production line that previously had badged them
Epiphone.
I was given a few shop stock ones that were dead out of the box - design and
manufactuing quality was absolutely shocking

If you wanted, you could probably fly to the same chinese factory tomorrow,
and have them make you a range of "Cook" badged amps, and it would be
identical to the Epiphone/Grainger and whoever else had the same idea.




Gareth.
 
Gareth Magennis <sound.service@btconnect.com> wrote in message
news:cpDHr.469970$S84.126685@fx23.am4...
"N_Cook" <diverse@tcp.co.uk> wrote in message
news:jsmb6t$7f3$2@dont-email.me...
Anyone know anything about this company?
RoHS and tick N222 stickers on the back and and so the problem is the
usual
for that .
But unusually the phrasing with it is "Made in P.R. China". Bought by
the
owner from new. The idents on the overlays on the pcbs have been
scratched
off. The paper label over the Asic/Pic on the digital board has been
scratched off. Also on that daughter board SMD IC with bogus Philips
logo.
Badly done re-work on traces to a 15V regulator at some point.
Seconds/failed-test boards coming through a back-door from ,say, Peavey
production line and sold on ?





Grainger were amps that the now defunt Sound Contol had made in China.
They
apparently came off the same production line that previously had badged
them
Epiphone.
I was given a few shop stock ones that were dead out of the box - design
and
manufactuing quality was absolutely shocking

If you wanted, you could probably fly to the same chinese factory
tomorrow,
and have them make you a range of "Cook" badged amps, and it would be
identical to the Epiphone/Grainger and whoever else had the same idea.




Gareth.
Click to expand...
I wonder what the internal build quality of the relays are , maker's names
Good Sky and Hui Ke.
So far 3 problems in the PREA found plus one made by me in the process of
removing a crimp spade (more solder on the contact side, than the solder
side , bled through from the wiring side) and of course I will have to
demount the PA for pre-amptive dealing with the "usual suspects" solderings
there.
 
"N_Cook" <diverse@tcp.co.uk> wrote in message
news:jsn5gn$8hv$1@dont-email.me...
Gareth Magennis <sound.service@btconnect.com> wrote in message
news:cpDHr.469970$S84.126685@fx23.am4...


"N_Cook" <diverse@tcp.co.uk> wrote in message
news:jsmb6t$7f3$2@dont-email.me...
Anyone know anything about this company?
RoHS and tick N222 stickers on the back and and so the problem is the
usual
for that .
But unusually the phrasing with it is "Made in P.R. China". Bought by
the
owner from new. The idents on the overlays on the pcbs have been
scratched
off. The paper label over the Asic/Pic on the digital board has been
scratched off. Also on that daughter board SMD IC with bogus Philips
logo.
Badly done re-work on traces to a 15V regulator at some point.
Seconds/failed-test boards coming through a back-door from ,say, Peavey
production line and sold on ?





Grainger were amps that the now defunt Sound Contol had made in China.
They
apparently came off the same production line that previously had badged
them
Epiphone.
I was given a few shop stock ones that were dead out of the box - design
and
manufactuing quality was absolutely shocking

If you wanted, you could probably fly to the same chinese factory
tomorrow,
and have them make you a range of "Cook" badged amps, and it would be
identical to the Epiphone/Grainger and whoever else had the same idea.




Gareth.


I wonder what the internal build quality of the relays are , maker's names
Good Sky and Hui Ke.
So far 3 problems in the PREA found plus one made by me in the process of
removing a crimp spade (more solder on the contact side, than the solder
side , bled through from the wiring side) and of course I will have to
demount the PA for pre-amptive dealing with the "usual suspects"
solderings
there.
Click to expand...
Does yours have a digital reverb PCB?
I seem to remember some of the ones I saw had them and they generated a ton
of hash.
The manufacturers had done a few local bodges to try and get rid of it, but
presumably it was a basic design fault that fed it through the power
supplies/earths.

Another one had a weird fault I can't fully remember now - I eventually
concluded it must be a layout or PCB problem (remember the Marshall PCB),
and thus unfixable.
So I didn't waste any more time trying to fix it.

I wasn't best impressed with these amps at all.



Gareth.
 
Gareth Magennis <sound.service@btconnect.com> wrote in message
news:VnGHr.514652$4v3.181608@fx08.am4...
"N_Cook" <diverse@tcp.co.uk> wrote in message
news:jsn5gn$8hv$1@dont-email.me...
Gareth Magennis <sound.service@btconnect.com> wrote in message
news:cpDHr.469970$S84.126685@fx23.am4...


"N_Cook" <diverse@tcp.co.uk> wrote in message
news:jsmb6t$7f3$2@dont-email.me...

Does yours have a digital reverb PCB?
I seem to remember some of the ones I saw had them and they generated a
ton
of hash.
The manufacturers had done a few local bodges to try and get rid of it,
but
presumably it was a basic design fault that fed it through the power
supplies/earths.

Another one had a weird fault I can't fully remember now - I eventually
concluded it must be a layout or PCB problem (remember the Marshall PCB),
and thus unfixable.
So I didn't waste any more time trying to fix it.

I wasn't best impressed with these amps at all.



Gareth.
Click to expand...

The digital effects includes reverb/delay . Not just that faux SMD Philips
but some other SMD chip with pins bent-fomed under, to solder into the
available space - how are those supposed to be soldered properly - will have
to remove this sub-board to see how bad it could/will be. I see a pressure
pad on that IC coming intp play as a pre-emptive, if its as bad as it looks
skew-on
 
Crackley master vol pot seems to be due to DC getting on the wiper, not from
either end of the pot track but coming out of a 4580 dual opamp input , when
varying the pot . It is directly connected to the wiper so perhaps a few
hundred ohm should go in line as well as a new IC. The pot track was bad so
perhaps with some DC getting through a blocking cap was enough to disrupt
the IC input
 
Horrendous DC bangs have gone , replacing that 4580 with TL072. Maybe both
op-amps set as unity-gain followers is something to do with the failure.
Also replaced the 47uF, 63V electro and wire link to MV wiper with 200R.
Have to replace both treble pots before I'm in a position to comparitive
check the f-resp with 200R and shorted but seems ok just monitoring the
output audibly.
So of course Epiphone Triggerman 100H would likely be susceptible to the
same failure, whatever precisely caused it.
 
No observable (to 0.2% measurement) difference, 200R or 0R, 60 Hz to 10KHz.
If the opamp failure was due to excess dV/dt then I doubt it would stop it
recurring with a bad pot /cap in the future
 
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