SELF POWERED SPEAKERS

[Roland N R]

For some time now compact excellent sounding amps have been available using Power Opamps. For example the 47 Labs Gaincard 25 watt stereo amp runs $3300 is tiny and comes very close to SET quality sound. These are built with a simple Power supply, a power opamp and about 9 parts. Don't get simpler but $3300!!!. Never fear DIY runs about $100 and it is easy!!

You can make a 25 watt amp using the LM1875 chip or a 50 watt amp with the LM3875. Imagine your own self powered HE speakers with close to SET quality sound but cheap and easy. Check under Gainclone in the web or under tweaks/DIY in the HE speaker asylum.

[Russellc]

I saw some ******r a while back about it, but never had a handle on what this gain clone thing is. Could you please elaborate? It sounds very interesting. I will check the internet, I was once given a site about it, but it led to a site about all sorts of solid state items and I never located it.
Thanks,
Russellc

[Russellc]

Sorry, I keep using the c-h-a-t-t-e-r word.

Russellc

[Roland N R]

My favorite amps have always been tube designs. SS amps I could tolerate for PA and sound reinforcement work but integrated circuits Op amps I always believed were the lowest point in amplifier design. Then I start reading about these simple power op amp amplifiers...golden ears saying "close to SET sound" and how guys are selling off their Krells and fancy SS amps to use these 25-50 watts tiny amps!!.

As mentioned above they are the simplest of design almost the SS version of SET amps. They have a simple low voltage bipolar power supply with only a 1000MF cap, an LM1875 or LM 3875 power op amp chip a few resistors and one or two caps and that is it....about nine parts all together!! The entire circuit fits in less than 2x2" and parts are in the $50-100 range. The commercially made 47 labs Gaincard sells for over $3K!!! The trick to getting close to SET sound out of these is to keep pathways very short especially the feedback loop (yes feedback).

Now my interest in these amps is primarily for driving HE speakers ideally as self powered speakers. I can see adjusting the freq input into these amps with inductors and/or caps or active XO and then Bi or Triamping with the amp right on the speaker. Here we finally have the combination of excellent sound quality and DIY easy to make at a low price.

If interested just type Gainclone in your search engine for more details. Do report back if you try it.

[MLVA123]

I'm currently constructing a DIY ST35 clone to drive my altec gear that I'm amassing
For those of you looking into tube amps, you probably got horrific sticker shock like I did - so I'm going the DIY route. Shannon over at DIYTUBE.COM is a great guy with an awesome kit and a really helpful attitude. The nice group of ppl over there forms quite a nice DIY support group. You can put this kit together for ~$350...check it out.
-ML

[Russellc]

Sad but true. To venture into tubes is expensive to do "off the rack". Tube DIY is the way to go. A relative novice can study up a little, become familiar with parts, look at a bunch of schematics, Look at how those that knew what they were doing i,e. old marantz, mcintosh, dyna etc., and dive in. The parts are large and easy to figure out, no micro chips and complicated boards. Plus, it makes it affordable! Plenty of kits out there for the less adventurous. However, I am going to experiment with the gain clone idea, even though I own no amp that isn't tubed, and haven't for years. This gain clone biz sounds taylor made for high efficency speakers like altec.

Russellc