Hoffman Amplifiers Tube Amplifier Forum

Other Stuff => Solid State => Topic started by: rzenc on August 13, 2012, 02:31:50 pm

Title: SS bass amp
Post by: rzenc on August 13, 2012, 02:31:50 pm

Hello!

I was asked to build an Acoustic 370 bass amp. It's a SS amp. I have never listened/played thru one. Searched schem but on the ones I found there was no voltages readings/marked. Also, there was no info regarding PT secondaries...
What I did find was a site which offered CAD drawings of Pcb's and possible compatible parts, but it's taxed ~ US$20,00.
Before proceding into this, I would like to hear your opinions about this amp.
I'm kind afraid of not getting the right 'replacements'/compatibilities to make it work right.

Also, I read somewhere that John Paul Jones used it on L.Z. Live Performances...but don't know how close to reality it actually is...

Any info is greatly appreciated.
Many thanks in Advance!!!

Best Regards
R.

Title: Re: SS bass amp
Post by: Willabe on August 13, 2012, 03:35:52 pm

My bass player had one of those amps for years and IMO they sound real good. But the speaker cab is a folded horn and has a lot to do with the over all sound of the amp. + the speaker cab is about the size of a small refrigerator, almost the same weight too.   :laugh:


                Brad      :icon_biggrin:

Title: Re: SS bass amp
Post by: PRR on August 13, 2012, 11:23:14 pm

I've worked with hi-power SS amps for decades. I would not attempt a 365 Watt monster, especially today. You can buy such amps pre-made cheaper than you can buy the first set of parts, and for-sure you will need more than one set of parts before you get something that will work all night.

Build the preamp and iconic cabinet, then go out to a guitar-store 400W PA rack-amp.

And indeed THE reason so many of the early greats used these amps is the 18" cone in a well-loaded (LARGE!) horn, plus the head would drive two horns which means the bassist could thump quite large venues without assistance from the house PA. Be sure your client needs and can carry such a rig. Modern house PAs are less-lame than the old days, Disco changed club-owner's attitudes to house systems, and sometimes the house system has more thud than an Acoustic.

Title: Re: SS bass amp
Post by: John on August 14, 2012, 03:49:53 pm

http://www.ebay.com/itm/Acoustic-370-Vintage-Bass-Amp-/330768561340?pt=LH_DefaultDomain_0&hash=item4d0357b4bc#ht_13467wt_1271 (http://www.ebay.com/itm/Acoustic-370-Vintage-Bass-Amp-/330768561340?pt=LH_DefaultDomain_0&hash=item4d0357b4bc#ht_13467wt_1271)

Bidding is not over, but PRR is right. You can't come close to building an amp for what you can buy a good used one for.

Then again, we don't do this to save money.  :icon_biggrin:

Title: Re: SS bass amp
Post by: rzenc on August 22, 2012, 08:41:39 am

Many thanks for your thoughts guys!!!

So, what do you think about it's preamp? As I said, I have never heard/played one personally.

Thanks in advance!

Best Regards

R.