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Wow!I'm excited as for the first date!

3/17/2004 9:58 PM
Le Basseur Wow!I'm excited as for the first date!
..wich,in fact,it is,in some way...  
Today I got on repair the most unexpected amp ever.  
It's an Acoustic model 164 in a near mint condition (the leather handle is half-broken:)) and it requires a re-capping and retubing job.  
See it at:  
I'm very happy to have it in my house because where I live there's absolutely NO TRACE of Acoustic amps and always wanted to lay hands at least once in a lifetime on such a legend.  
Besides,from the above link the 164 model seems to be pretty rare even in the States;what do say the old foxes in this forum about that,it's really so scarce?  
On a first view,the configuration resembles Mesa,both as circuit but especially by the look of the PCB's.However,there are some unique features,such as the dual (FET and tube) switchable input stage and the two coax potentiometers (both have the "gain" inside and the "master" outside).  
Oh,I forgot mentioning the massive EVM12L driver...:)  
Please excuse my enthusiasm,but I felt like I'd share my latest joy with people being able to understand such an event.  
There is a big chance to buy this beast from the owner,because he needs some smaller amp in the 18W range for his gigs.I'm preparing for a fair trade (I don't know yet how much I'll have to pay,but I began to sell my curtains and my cat:)),because I think it's not the case for tearing down the price with false arguments.  
From the other point of view,I'm temporarily stuck,because I just don't know if the amp requires a mod or not.  
What do you guys think?  
Have you had a 164 on the shelf?And if yes,what did you do with it?  
A big thanks,  
(one piece of a happy)  
Le Basseur:):):)
3/18/2004 2:32 AM
Le Besseur,  
I'd be interested in your take on the build quality of this amp. I owned a 164, I had a friend who owned the 165 (164 in a hardwood cab). The sound of my amp was touchy, I could never get it to sound the same two days in a row :( Little things kept going wrong with it, and eventually the tech I took it to told me to sell it. He claimed that there were parts of the circuit that couldn't be fixed because the parts were unobtainable. I don't know whether he was full of sh*t and just didn't want to deal with the amp anymore, but I did unload it. I never really liked the sound of this amp anyway.  
Anyway, my $.02.
3/18/2004 8:55 AM
Le Basseur
Hi Steve,  
"I'd be interested in your take on the build quality of this amp.(...)He (the tech-n.n.)claimed that there were parts of the circuit that couldn't be fixed because the parts were unobtainable."
After reading your post,I took a (second) good and long look at the schematic,chassis and PCB's just to be sure I didn't miss something because of the last night's euphory;).Well,the status didn't change a bit...there is NO part in this amp you couldn't find.Everything found in this amp could be replaced with an exact replica or,in the worst case,with available substitutes.(Mind you,I live in an small European country,thus for a US tech there should be NO problem when getting the parts).  
Well,there are some irreplaceable parts on this amp,such as knobs or fuseholders :),but that's all.  
As I said before,the 164 is very close to the older Mesa amps regarding the way it's build and the PCBs' overall aspect.To be honest,I kinda hate this way of approach for technical reasons (I'm more happy with a true p-t-p or at least with an eyelet cardboard;)),and that's because of some previous unhappy experiences regarding some Mesas I had on repair.BUT,this amp can be forgiven for this apparent flaw,because after more than 20 years of duty didn't lost it's integrity (on some Mesa MKII's,the PCB's were literally "baked" and it was a PITA to re-shape all those burned holes and interrupted and exfoliated copper traces).  
To keep the story short,it's most probable the tech you mentioned was too lazy or too stupid (...maybe he didn't realise the similarity with Mesa's circuits?!?:D).  
About the fluctuating behaviour you mentioned,it's kinda strange,but not impossible.If you say the amp had already some problems,OK,but,again,there's nothing insolvable about it.Didn't like the sound?Maybe you could try another driver instead of the original EV...who knows?  
Anyway,in the next week I'm gonna put it "on legs" and you'll get every detail you might want about it's behaviour.  
And now,something for all the readers of my first post:  
...OK,let's put it in another way:  
"Last night I got on repair a MF of an amp,wich I don't like at all but I never saw such a thing before,and I'd want to know what you think about it."  
How's this,it sounds better?;)  
I really appreciate the attitude of those who read my first post but eventually didn't reply in a negative manner just because were too sensitive on my last night joy :D,but I can take any cold shower from you,folks!:)  
Le Basseur
3/18/2004 5:27 PM
Dave B

I don't think we've seen an Acoustic 164 schematic before. (Well, I haven't) Are you able to post it?  
3/18/2004 5:45 PM

I can share one hard won piece of info on these amps...  
Don't switch the impedance selector on the OPT under load. I was testing one of the models with out the graphic eq, and killed the xfmr.  
That's probaly true for all amps, eh?  
3/18/2004 8:41 PM

might have been a make before break, so it shorted out the secondary..  
3/18/2004 9:08 PM
Le Basseur
"That's probaly true for all amps, eh?"
Painful true!;)
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