SUNN Concert PA for bass?

[Bass V]

I'm inclined to say YES! OF COURSE! but who here has actually run their bass thru one to know if they are something special or not? this may be the same things Leslie West linked together to devastating effect in Mountain's prime and helped give him his iconic tone. it's being sold at an insane giveaway price and won't last long but the seller is 'unavailable' at the moment...

 

[Redbrangus]

It's a 100-watt, first-generation solid-state amplifier from about 1971...personally, I wouldn't get too excited about it. I believe I did read where Leslie West played through a Sunn PA head in the early days, but I think that was a Coliseum series...they were rated at 300 or so watts. If it's like most of the early vintage solid-state amps, I reckon it would have a certain real 'grit' to it, but whether or not it's a useful sound would be up to the user. I certainly wouldn't expect it to be anything special, especially not for a bass amp. Just IMO, of course.

Now, having written that, I expect we'll be hearing from players who believe it possesses some of the most magic mojo ever manufactured.

 

[Redbrangus]

I found an article, this one in Guitar Player (https://www.guitarplayer.com/players/leslie-west-decodes-his-mississippi-queen-tone) where Leslie West claims it was a Coliseum PA head, but goes on to describe it as having 4 KT88 output tubes. So nothing like this solid state head. Those early Sunn tube amps employed the Dynaco hi-fi power amps designed by Dave Hafler, which were about as good as any amps made in the day. They also appropriated the Dynaco pre-amp circuit from the highly regarded PAS-1 hi-fi preamps for their input stage. All the Dynaco stuff was available in kit form (with extensive documentation), which probably figured heavily in Conrad Sundholm's decision to go that route. At any rate, these were the amps Sunn built their early reputation on. Like pretty much everyone else, they struggled some in the transition over to transistors, and this Concert PA amp is part of that first-generation effort. They did a lot better than Fender did with their first attempt at solid-state, but still.... ?

 

[Bass V]

I found an article, this one in Guitar Player (https://www.guitarplayer.com/players/leslie-west-decodes-his-mississippi-queen-tone) where Leslie West claims it was a Coliseum PA head, but goes on to describe it as having 4 KT88 output tubes. So nothing like this solid state head. Those early Sunn tube amps employed the Dynaco hi-fi power amps designed by Dave Hafler, which were about as good as any amps made in the day. They also appropriated the Dynaco pre-amp circuit from the highly regarded PAS-1 hi-fi preamps for their input stage. All the Dynaco stuff was available in kit form (with extensive documentation), which probably figured heavily in Conrad Sundholm's decision to go that route. At any rate, these were the amps Sunn built their early reputation on. Like pretty much everyone else, they struggled some in the transition over to transistors, and this Concert PA amp is part of that first-generation effort. They did a lot better than Fender did with their first attempt at solid-state, but still.... ?

good analysis and definition on the matter even without the cool link!
I didn't research the PA yet and despite no tubes or Mountain connection I might be even more intrigued with this one now cos the mega watt tubed Coliseum could only be used in a ...well, in a Coliseum! lol I might actually find a low volume use for this if it sounds good. I like SS these days, no tube hassles and some SS can sound warm and tube-ish if you're lucky. imo for a mere $55 it's worth just the conversation piece factor.

 

[edbass]

good analysis and definition on the matter even without the cool link!
I didn't research the PA yet and despite no tubes or Mountain connection I might be even more intrigued with this one now cos the mega watt tubed Coliseum could only be used in a ...well, in a Coliseum! lol I might actually find a low volume use for this if it sounds good. I like SS these days, no tube hassles and some SS can sound warm and tube-ish if you're lucky. imo for a mere $55 it's worth just the conversation piece factor.

That transistor Concert PA Control Amp was rated at 90 watts RMS, introduced in 1969 I believe.
The Coliseum PA amp Leslie West used in Mountain (and the Beach Boys actually used as a PA amp) was an, albeit conservatively rated, hand wired, all tube 120 watt amp.
As a side note, I'm pretty sure Mountain got those amps from the Jimi Hendrix Experience when Jimi's Sunn endorsement expired.
Sunn also produced a 60 watt all tube Studio PA using the same preamp configuration.

Leslie West's Coliseum had the same hi-fi output stage as the venerable Sunn 2000S bass amp, but with an additional half of a 12AX7 in the 1rst stage for more gain, as it was intended to amplify dynamic microphones - not even remotely close to the early Sunn transistor amp you found, tonally or in market value.

The original Sundholm era Coliseum and Studio PA amps made outstanding bass/guitar amps, a little higher gain than the other very hi-fi Sunn offerings.
That transistor amp would likely sound kinda thin and anemic by comparison; "warm and tube-ish" takes actual tubes, but for $55 who cares?

 

[Bass V]

That transistor Concert PA Control Amp was rated at 90 watts RMS, introduced in 1969 I believe.
The Coliseum PA amp Leslie West used in Mountain (and the Beach Boys actually used as a PA amp) was an, albeit conservatively rated, hand wired, all tube 120 watt amp.
As a side note, I'm pretty sure Mountain got those amps from the Jimi Hendrix Experience when Jimi's Sunn endorsement expired.
Sunn also produced a 60 watt all tube Studio PA using the same preamp configuration.

Leslie West's Coliseum had the same hi-fi output stage as the venerable Sunn 2000S bass amp, but with an additional half of a 12AX7 in the 1rst stage for more gain, as it was intended to amplify dynamic microphones - not even remotely close to the early Sunn transistor amp you found, tonally or in market value.

The original Sundholm era Coliseum and Studio PA amps made outstanding bass/guitar amps, a little higher gain than the other very hi-fi Sunn offerings.
That transistor amp would likely sound kinda thin and anemic by comparison; "warm and tube-ish" takes actual tubes, but for $55 who cares?

who cares is exactly the question cos somebody else got it lol sucks to be broke at opportune moments.
no doubt the vast majority of SS amps are sterile in comparison but with luck exceptions to the rule are out there, older brands like my obscure Canadian VT Beta 60 1x15 combo in the right settings can emulate the warmth and tubey response. oddly it's a dark amp and really works for that sound. even my Fender B-DEC 30 can get close, add in some extra grit n grind from a tiny MICRO CUBE RX and I'm nearly into Felixland, not that those will slay my vintage pieces but they need volume to breathe and at apt. levels I'm getting away with some satisfactory fun without all the neighbors flipping out.
the best of those SUNNs were pretty great, Leslie merely stumbled into his classic setup with the PAs and the rest was history, while Felix got those juiced Hendrix heads which I guess Jimi never even got to use. they created a unique sound for Mountain and it is sorely missed today, especially with so few examples showing them in their early prime, at their best almost nobody could touch that quartet.