GainClones & 4 Ohm Loads

[SRMcGee]

Folks:

Has anyone tried their GainClone out with a difficult speaker? I am building four BrianGT-based GainClones with a friend, and he is interested in pairing one of his with a pair of Thiel speakers (the 2.6, I think), which has 4 ohms impedence.

Is anything likely to blow up? Will GainClones acquit themselves with honor under a tough load? Will the Thiels' sound be adversely affected? All knowledgable responses are appreciated.

Thanks,
Scott

[chipco3434]

I am running PE/Pioneer 4"/Dayton tweet DIY line arrays with gain clones... one intergrated the other not. The speakers are about 5 ohm nominal.

I can run it until my ears bleed but them amp never complains... the CD will skip, but the amp doesn't fuss.

Anyway, the internal (SPIKE... TI trademark) will protect the chip from most stupid stuff.

[usekgb]

The ideal way to run a gainclone in to a 4 ohm load is to use the paralled configuration. You can do this with two of BrianGT's boards if you wish. Run the signal input to both gainclone inputs (or use an input buffer if you wish), and put a 1% (even better, use a 0.1%) 0.1 ohm 5 watt resistor on the output of each chip amp. Tie these two outputs together, and you have a gainclone that can deliver twice the current of a single chip version. This will easily push your 4 ohm load.

Cheers,
Zach

[BrianGT]

I use my gainclone with my 4 ohm Seas Thor TL speakers, and I have had no problems. I am using a 320va 2x24vac transformer, and I can turn it up all the way without problems. This creates volume levels that are too loud to listen to.

I would recommend trying the standard configuration first. As for the 2x24vac voltage, it seems to work fine for me. It seems that the datasheet is conservative in their voltage ratings.

--
Brian

[kestrel200]

Use a transformer rated at 18V & you'll be fine. I used a 22V and power an MTM rated at 4ohm at very loud levels and the sides of the case get pretty hot but the amp still doean't clip. But an 18V would be better according to the spec sheets.

[carlosfm]

Originally posted by SRMcGee
Has anyone tried their GainClone out with a difficult speaker? I am building four BrianGT-based GainClones with a friend, and he is interested in pairing one of his with a pair of Thiel speakers (the 2.6, I think), which has 4 ohms impedence.

It's not just a question of manufacturer's rated impedance.
Most modern speakers (the trend is bass-reflex) have impedance dips in the bass region and 4 ohm speakers can go lower in some frequencies.
You don't know until you try the amp with those speakers.
My guess is that it won't drive them, no way.
The typical GC can't drive properly a pair of B&W 602 S3, and they are rated 8 ohms! But they have impedance dips to less than 3 ohms.
Rest assured that not every commercial amp can drive them anyway, you need a good one.

Some people don't notice when the amp is not driving their speakers properly.
They simply don't mind to have their house shaking with untight bass, some guys like it!

Originally posted by SRMcGee
Is anything likely to blow up? Will GainClones acquit themselves with honor under a tough load? Will the Thiels' sound be adversely affected? All knowledgable responses are appreciated.

No problem for the amp.
But it will sound bad, because bad bass spoils everything, including midband and treble.
You can parallel two chips per channel, and maby then the amp will behave with those speakers.
You need a big trafo or one per channel.