760 leslie quit working was sounding good.

[Drawbar Dave]

As I wrote in the first response to your help request: "The most obvious reason for burning up R82 would be a short in the driver transistor it's attached to, Q12."

Never mind, it became quite an enjoyable thread :-)

[David Anderson]

Anyway the 760 that stopped working all of a sudden, ended up being the Q12 driver transistor. Boy does it sound good now, no hum either! thanks guys!

As I wrote in the first response to your help request: "The most obvious reason for burning up R82 would be a short in the driver transistor it's attached to, Q12."

[tom hoffstatter]

Anyway the 760 that stopped working all of a sudden, ended up being the Q12 driver transistor. Boy does it sound good now, no hum either! thanks guys!

[Drawbar Dave]

Over here, at least, the 760 was initially introduced as the '760 Walnut' and '760 Black'. I sold quite a few and had a 760 Walnut on my T400. Both in the 147/122 cabinet but with the 'black' one having a sprayed on black crackle finish and two rather small handles. It was only when the tolex covered 825 and 760 'Pro Line' models were introduced that the 760 Walnut became the 770. Hammond Europe (always a law unto themselves) came up with lots of variants on the 760, like the '760N' shown at the right!

How does the shortie 760 in the 45 cabinet sound, Pete? Enough bass? I know they always pushed the 147 over the 145 for its 'extended bass response', but I never found the 145 lacking in any way.

The wood cased 760 I scored as part of a package deal with my BX-3 recently was a crackle finish. Unfortunately it had been cut in half and had open hand holds cut in the base enclosure. The owner had also cut out the upper louvres into large rectangle holes which for me was the point of diminishing returns and I sadly gutted it and send the case to landfill. I am planning to finish my own wood cabinet 760 in crackle finish as it is matt black at the moment. Having owned a 122 and 147, the 760/770 always does it for me!

[Sweet Pete]

Thanks for the idea enor. I 'borrowed' it! Nickname for the shorty? Magnus Maximus of course!

[enor]

Andy, the shorty has lots of bass.Great sounding box.

Let me second that - I also have such a box (760 guts in a 142 cabinet). Bass is maybe a wee bit softer than a tall model, but on the other hand it's tighter and more responsive.

[Sweet Pete]

Andy, the shorty has lots of bass.Great sounding box.

[andyg]

Over here, at least, the 760 was initially introduced as the '760 Walnut' and '760 Black'. I sold quite a few and had a 760 Walnut on my T400. Both in the 147/122 cabinet but with the 'black' one having a sprayed on black crackle finish and two rather small handles. It was only when the tolex covered 825 and 760 'Pro Line' models were introduced that the 760 Walnut became the 770. Hammond Europe (always a law unto themselves) came up with lots of variants on the 760, like the '760N' shown at the right!

How does the shortie 760 in the 45 cabinet sound, Pete? Enough bass? I know they always pushed the 147 over the 145 for its 'extended bass response', but I never found the 145 lacking in any way.

[Sweet Pete]

Never touch the best one! Start with the worst and move up.

I disagree Tim!
When they don't need more than a basic service,having a pair ready fast and easy was on my radar.

The two that needed the least work and are gigging boxes.They are already in 122 and 45 cabs. Already in use and hum free loud and clean!
Some electronic cleaning and solder reflowed,some triacs replaced.Not much needed surprisingly.Basic service as in the manual.
Twenty five hours each so far,no glitches.

The other two still work,will get a thorough check, and are in need of cosmetics. I have two full size wood boxes already to recase them.
To their credit,Leslie did introduce the 770 not long after the 760.
No worries,I recycle the decks and hardware. Lots of useful things to harvest. Apologies to fans of tolex covered Leslies.
As in the evolution of many things,louder and plastic go together!
That 430 amp plate with orange boards are spares only. Not as well made as the green boards.

At this time nine of twelve boxes in the collection are ready to use.
Can't lose on this. Well......maybe my hearing LOL.

[Tim_at_Jonas]

I lucked out so far with my 760 finds,and will start by rebuilding the '71 which sounds best of the four.

Never touch the best one! Start with the worst and move up.

[David Anderson]

I did restore an early orange/yellow boarded PSU from an 825 once. The traces were coming off in places and I had to install a few jumpers to make it work. I think the later green boards were alot more durable.

You see the same thing in Combo Preamp circuit boards. Early ones were phenolic and were easily damaged. Later ones were fiberglass.

[Drawbar Dave]

The power supplies are effectively interchangeable, and at this point in history, we do find lots of Leslies that have been repaired or modified via amp or power supply swaps. I've lost count of how many times I've found a 147 amp in a 122 cabinet or vice-versa.

I did restore an early orange/yellow boarded PSU from an 825 once. The traces were coming off in places and I had to install a few jumpers to make it work. I think the later green boards were alot more durable.

[David Anderson]

Yes nuts on studs. Strangely the PSU has the later 2 x triac design rather than the earlier 4 x SCR setup. I'm not sure what colour that board is yet - needs cleaning. It might have been modified to the later triac circuit. I believe I have done this in the past with a couple of links added.

The power supplies are effectively interchangeable, and at this point in history, we do find lots of Leslies that have been repaired or modified via amp or power supply swaps. I've lost count of how many times I've found a 147 amp in a 122 cabinet or vice-versa.

[Drawbar Dave]

Interesting PCBs. The capacitor date codes point to 1972 construction, and the mounting hardware is different from all the boards I've seen. Typical PCBs are held to threaded stand-offs with hex-head machine screws. Are those held in place with nuts on studs?

Yes nuts on studs. Strangely the PSU has the later 2 x triac design rather than the earlier 4 x SCR setup. I'm not sure what colour that board is yet - needs cleaning. It might have been modified to the later triac circuit. I believe I have done this in the past with a couple of links added.

[David Anderson]

Interesting PCBs. The capacitor date codes point to 1972 construction, and the mounting hardware is different from all the boards I've seen. Typical PCBs are held to threaded stand-offs with hex-head machine screws. Are those held in place with nuts on studs?