SWR Studio 220

[Precisionb87]

I have what I think to be a pre-fender SWR Studio 220. I will be selling it very soon, but I first I need to get some info on it first. (I am not particularly thinking of selling this through talkbass, so please do not flag me)
Maybe somebody can help shed some light.
Judging by the serial number, what year was it made?
Is there a website that can help me identify that?
How much are these things worth these days? (good condition, no issues)
Thanks for all the input.

[wave rider]

Don't know if these will answer your questions:
SWR® - STEP UP!™

SWR® - STEP UP!™

I didn't remember that the 220 was so light...

=wr=

[akflyer]

Regarding value, I sold mine about a year ago for $225.00.

[pbagley]

Just bought one here on TalkBass for 190 shipped. I saw a later Studio 220 1-15" combo today for $375 in a local shop.
Your amp seems to be later in the production run since it has the detachable power cord.

From my very limited research these seem to be decent amps, but short on power compared to more recent bass heads. People seem to want a lot more power than they used to. I've gigged with a 50 watt amp and had the drummer ask me to turn down. If you can find cabs you like the sound of that are reasonably efficient then 200 watts is plenty.

I'm hoping that "vintage" SWR prices take off like a rocket ship in a few years. 'Til then I'll be enjoying a decent sounding amp.

I would be interested in SWR serial number to year of manufacture info too.

- Paul

[T-Bird]

Hi.

It has the "classic" SWR preamp section and one discrete design SWR "classic" 200W power amp section. The SM 400 had two of those power amp modules.

IME the mfg date can usually be found on either the PCB's or on the transformer. Assuming they're original of course.

Being seemingly low on power can be remedied by EQ:ing the extreme lows down completely or by using a HP filter. Steve's desire to have a Hi-Fi-like amp IMHO worked against every SWR amp as the lows robbed a lot of the percieved wattage.

Since the power amp is of a traditional discretes design, the amp requires a periodical bias check and adjustment. It can creep pretty badly and the result is even more heat than normally and more loss of power.

Being low on power is IMHO moot, especially nowadays, as it's of 19" design, has an internal cross-over, power amps are cheap and 200W is more than enough to drive mids+higs.

I'll probably never sell mine (did sell my SM400 back in the day though ).

Regards
Sam

[1n3]

I've always found this to be an interesting amp, mostly because of the four semi-parametric filters and crossover. The SWR page (second link posted) lists the weight at 13.5 lbs (6.12kg). That's surprisingly low for that era and power. Can anyone confirm this weight?

BTW, here's an interesting mod to the SWR tone control circuit: SWR Aural Enhancer Bypass

[T-Bird]

HI.

Originally Posted by 1n3

The SWR page (second link posted) lists the weight at 13.5 lbs (6.12kg). That's surprisingly low for that era and power. Can anyone confirm this weight?

Mine's (fixed power cord) 6.15Kg, so at least mine falls pretty close to the claim.

I do have to admit that it's been a sweet while (years) since I used that amp since I'm almost completely a tube kinda guy, but if more versatility, less weight, perhaps more back-line power and/or SS is required, this is the amp of choice for me.

Regards
Sam

[1n3]

Originally Posted by T-Bird

Mine's (fixed power cord) 6.15Kg, so at least mine falls pretty close to the claim.

Thanks - that was quick. Good to know.

[pbagley]

Originally Posted by T-Bird

Hi.

Since the power amp is of a traditional discretes design, the amp requires a periodical bias check and adjustment. It can creep pretty badly and the result is even more heat than normally and more loss of power.

Regards
Sam

Sam,

Can you direct me to information on how to check and adjust bias on the Studio 220 power amp?

Thanks,

- Paul

[T-Bird]

Hi, Paul.

Here's a link to the "oscilloscope method" for SM400.

http://mhumhirecords.org/DIYpages/sc...s/SWR/Bias.pdf

I remember having a less equpment requiring instructions as well, but those have been lost, perhaps someone still has them. That SWR specific link above was posted here at TB, so the credit for the link goes for that orginal poster.

My amps have performed flawlessly on the power amp side of things, so I haven't biased mine, but I do have biased (reluctantly ) a few similar topology amps using the "cross-over" distortion method. I'm not 100% certain that the method works on the ST220, it should, but I'll check that in a few weeks.

Regards
Sam

[pbagley]

Thank you!

[T. Alan Smith]

I recently acquired a Studio220 and it's much more inspiring to play thru than my LMII.

[okiecruffler]

I love mine, wouldn't part with it. As far as power (if you really need more) you can Bi-amp or it's got a great DI too.

[pbagley]

Not that vintage - has the removable power cord so a later production run.