When you say you had a PA fry your combo, were you di'ing out of the combo into the PA? Could the PA have sent phantom power over the connection?
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Failed Ampeg Combos
- Thread starter moonoid
- Start date
When you say you had a PA fry your combo, were you di'ing out of the combo into the PA? Could the PA have sent phantom power over the connection?
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He said:
"I had a PA system fry out a 300 Watt Peavy over some issues that to this day I have no idea what it was but could be something you listed. How would a bass player go about checking? When I plug in my power strip I get a reading on the voltage but that is all I can see".
She said:
"When you say you had a PA fry your combo, were you di'ing out of the combo into the PA? Could the PA have sent phantom power over the connection?"
I didn't know that the phantom power could do that, our medium gig PA head is all-or-nothing in this respect (EMX512Sc Yamaha). My sanger / twanger leaves the damn thing on irrespective of need, he must like the lights or something.
Can a dedicated mic cable with one of the pins pulled negate the phantom power input? Or would a cross-over cable from mic x 1/4" phone do as well?
He said:
"I had a PA system fry out a 300 Watt Peavy over some issues that to this day I have no idea what it was but could be something you listed. How would a bass player go about checking? When I plug in my power strip I get a reading on the voltage but that is all I can see".
She said:
"When you say you had a PA fry your combo, were you di'ing out of the combo into the PA? Could the PA have sent phantom power over the connection?"
I didn't know that the phantom power could do that, our medium gig PA head is all-or-nothing in this respect (EMX512Sc Yamaha). My sanger / twanger leaves the damn thing on irrespective of need, he must like the lights or something.
Can a dedicated mic cable with one of the pins pulled negate the phantom power input? Or would a cross-over cable from mic x 1/4" phone do as well?
When exactly? When they made amps that were underpowered for playing anything but oldies goldies jazz tunes at whispering volumes? ...Or when they started to make more modern and higher power amps that have always had a questionable reliability record?
Take SVT for example. Right in the very first revisions Ampeg manages to get tubes with excellent reliability record in very demanding service to fail when the amplifier is driven into clipping. ...Followed by several other revisions plagued by who knows what petty reliability issues from molex connectors to scorching PC boards or unoperative protection circuits.
Keep up with the good work Ampeg!
[/QUOT
When exactly? When they made amps that were underpowered for playing anything but oldies goldies jazz tunes at whispering volumes? ...Or when they started to make more modern and higher power amps that have always had a questionable reliability record?
Take SVT for example. Right in the very first revisions Ampeg manages to get tubes with excellent reliability record in very demanding service to fail when the amplifier is driven into clipping. ...Followed by several other revisions plagued by who knows what petty reliability issues from molex connectors to scorching PC boards or unoperative protection circuits.
Keep up with the good work Ampeg!
Own two Ampeg combos, an old B2 and a new BA108. The B2 is a tank, but it's had its share of issues along the way, particularly with the back plate on the pots coming apart. Haven't had any smoke-n-flame events with it, but who knows...it's older now and it might just have a flameout any day now. The newer BA108 isn't really in the same ballpark, but seems okay so far.
Also have an old Crate BX100T (the wheeled version with the pop out handle) which hails from the SLM assembly line. It's been very reliable in just about any situation I've placed it in.
Sound quality from all three is stellar, which is why I keep them around. Hopefully I'll avoid experiencing the problems others have discussed here.
Also have an old Crate BX100T (the wheeled version with the pop out handle) which hails from the SLM assembly line. It's been very reliable in just about any situation I've placed it in.
Sound quality from all three is stellar, which is why I keep them around. Hopefully I'll avoid experiencing the problems others have discussed here.
An update on the two failed Ampeg combos. Took them both to another reputable Manchester UK engineer in January. Now, three months later they are still not fixed! I've given up on them now. I'm not even sure if it's worth picking them up for the 15 inch speakers....are they worth anything at all?
I'm considering the new Fender Rumble 500w head and the new Fender cab - either a 4 by 10 or 1 by 15. Anyone tried these yet?
I'm considering the new Fender Rumble 500w head and the new Fender cab - either a 4 by 10 or 1 by 15. Anyone tried these yet?
there is a Fender Rumble club here on TB. Maybe take a look over there.
I am interested in the Fender Rumble 500 head myself.
Sorry to hear about the dead Ampegs. Nothing turns a player off quicker than gear that dies in a gigging situation.
I am interested in the Fender Rumble 500 head myself.
Sorry to hear about the dead Ampegs. Nothing turns a player off quicker than gear that dies in a gigging situation.
At least some of the pics of Teemuk's post seem to show evidence of a bad tube.... another appears to show a failed capacitor.... Pretty much all are pics of amps old enough to have age-related issues with some parts, particularly capacitors.
And, NEW tubes, which very likely are in those amps these days, are nowhere near the reliability of the old ones.
In the old days the best tubes you would ever get were the ones in the product when you bought it. The ones sold as replacements were just the ones no manufacturer wanted to use as original equipment. Yet they were still "good", they just had parameters that were outside the range the manufacturers wanted.
These days, as I know, we bought tens of thousands of tubes, whole shipments of tubes may have problems. One shipment we got would fail in two minutes if you cranked up the amp. We did manage to fix those, since a manufacturing step to "burn off" contaminants had been left off, and we could simply do that ourselves.
But others have all sorts of problems, bad welds inside, loose mica that can let tube elements touch, etc. new tubes have crappy quality control compared to the old days, mostly because the total market for tubes is really so small, but old production methods and QC were always oriented to very large volume production.
Dunno about "managing to get tubes to fail".... most of the older amps of all makes were made pretty cheaply, but the SVTs, for instance, were pretty darn solid and original ones are still working now, 45 years later. Even though the old units of all makes were often made cheaply, they held up well enough for a lot of them to still be around.....
It is probably more that old circuits which need good tubes, and newer less well-made tubes don't always mix well.
And, NEW tubes, which very likely are in those amps these days, are nowhere near the reliability of the old ones.
In the old days the best tubes you would ever get were the ones in the product when you bought it. The ones sold as replacements were just the ones no manufacturer wanted to use as original equipment. Yet they were still "good", they just had parameters that were outside the range the manufacturers wanted.
These days, as I know, we bought tens of thousands of tubes, whole shipments of tubes may have problems. One shipment we got would fail in two minutes if you cranked up the amp. We did manage to fix those, since a manufacturing step to "burn off" contaminants had been left off, and we could simply do that ourselves.
But others have all sorts of problems, bad welds inside, loose mica that can let tube elements touch, etc. new tubes have crappy quality control compared to the old days, mostly because the total market for tubes is really so small, but old production methods and QC were always oriented to very large volume production.
Dunno about "managing to get tubes to fail".... most of the older amps of all makes were made pretty cheaply, but the SVTs, for instance, were pretty darn solid and original ones are still working now, 45 years later. Even though the old units of all makes were often made cheaply, they held up well enough for a lot of them to still be around.....
It is probably more that old circuits which need good tubes, and newer less well-made tubes don't always mix well.
