Orange Amps Forum

hey folks...

i looked for this everywhere but didn't find a clear response.
i've seen quite a few GRO100 amps for sale with the pics and text faceplate, they look exactly like the OR120 from the same years.
was there an actual difference? wattage? circuit?

the GRO's were Matamp-built or something?

everybody raves over the "plexi pics only" sound, but then did this circuit change? now it turns out the pics-only faceplates were used up to 1975, which is OR120 territory all the way.

share to shed some light on this? thanks!

Pat.

The pre-amp is completely different from the OR-120. Also, there seems to be variation in GRO amps. Component values aren't consistent from amp to amp.

The major design details are all common to both amps; baxandall tone stack, FAC knob, split load driver, etc. So it does sound very similar to an OR-120. But, no, it's not the same amp. I'd say the GRO is less fuzzy and a bit more clear sounding. Both circuits sound vey good. I have both amps and love both amps.

There are schematics on the Orange amp field guide, but basically, the parts of the preamp are in a different order, and the component values are different.


-Nick

As far as I can tell, GRO100s were only made by Matamp for Orange. Matamp also made OR80s and OR120s, but none of the other subcontractors made GRO amps. And yeah, there's differences between an OR and a GRO, but there are also differences between different GROs. There were so few made, it almost seems like they were custom orders or an attempt on Matamp's part to get rid of extra parts. If I found a GRO100, I'd buy it before an OR120. You have a chance of getting the same or better tone and a way more rare amp.