QSC Series Three 3500 pro amp

[GMorris]

I picked up a late model QSC Series Three 3500 to power a couple of sonosubs but have been impressed with it powering my main speakers as well. It was apparently QSC's high-end model in the 80's. This model will put out 300 watts into 8ohm and 625 watts into 2 ohms at 0.1% THD. Dual mono and fanless as well.

I was wondering if anyone would like to make recommendations on some easy upgrades.... There is a dual op-amp on the input with a socket so swapping those in and out would be pretty easy. Maybe I should by-pass some power supply caps?? It sounds very good as is so maybe I should just leave it alone.

Here is a link to the owner's manual which includes a pretty in depth description (pg 18 in the pdf) as well as a schematic (pg 27 in the pdf).

http://www.qscaudio.com/pdfs/discontinued_products/SeriesThree.pdf

You can find these on ebay for under $300. Highly recommended.

[thylantyr]

I vote:

It sounds very good as is so maybe I should just leave it alone.

I will save you some money.

1. Buy some boooze
2. Get drunk
3. Convince yourself that you did do mods.

The next day, enjoy the improved sound of your modded amp.

[engr_dave]

1. Buy some boooze

Thylantyr,
I take it as a personal affront... that you wouldn't automatically assume any self-respecting DIY audiophile to already have a generous supply of booze on hand. :drinker:

[AJINFLA]

I've been using that very amp to power my dipole woofers for the last couple years. It will remain in my collection for as long as it works.
I let recordings, the room and my skill as a speaker designer (or lack thereof) determine the audio quality that I hear.
A fact of being human is that placebos do work, although many feel this simply does not apply to them. Unless your modifications harm the electrical performance of the unit, I see no harm in modifying and then convincing one self that there has been an audible improvement. If this adds to your enjoyment of the product, so be it.

cheers,

AJ

[Amphiprion]

Don't touch the amp.

Figure out the schematic instead. It will be much more satisfying.

[Dennis H]

Ditto what the other guys said. I've always been very impressed with the SQ of QSC amps. Maybe I'm deaf but they sound great to me.

[GMorris]

Thanks for the tips... I think I will leave it alone as suggested and enjoy it along with some high% imperial stouts sitting in the fridge. A wild excess of watts seems to have positive benefits on the sound of my mains and there is no fan noise. This amp is hard to beat for the price...