Gainclone supply voltage

[Nuuk]

I have now listened to my Gainclone monoblocks with both a +/-37VDC supply and +/-27VDC.

There is a very slight difference in tonal quality but not really enough for me to express a preference for one or the other. If I were forced to take one though, I would just opt for the lower supply!

I know that Peter Daniel prefers the lower voltage option but has anyone else tried different supplies and found a big difference in the sound?

 

[carlosfm]

Hi Nuuk,
I haven't tried other voltages, I use a 24v transformer on mine.
But what I can tell from looking at the datasheet is that if you whant your Gainclone to be stable with both 8 and 4 ohm speakers you have to pick a transformer between 20 and 24 volts, and no more.
I think the ideal would be a 22 volts transformer, to get a final voltage of around 30-31 volts.
It's a good compromise.

 

[Nuuk]

But what I can tell from looking at the datasheet is that if you whant your Gainclone to be stable with both 8 and 4 ohm speakers you have to pick a transformer between 20 and 24 volts, and no more.

Hi Carlos, that tallies with what somebody else told me about driving 4 ohm speakers.

I think what has happened is that so many of us have built Gainclones as an experiment, using what ever transformers we can find in the neighbour's dustbin 😉 that all sorts of voltages have been seen in these threads.

It may be a good idea to revise my transformer recommendations on the GaincloneFAQ page.

 

[mothman]

I'm driving 4 ohm speakers with my LM3886 amp and had been using a 2x25 volt trafo that gave me a 2x37 volt supply.
I had always felt this was on the high side based on the data sheets and just put a 2x18 trafo in(2x28) supply and I like it much better.
I can get into the volume more without the sound getting hard.
Also could one of you more learned chaps comment on the 'less voltage for 4 ohm load issue'is it a function of the amp being required to deliver more current and the supply rails maxing out or what?

 

[mhennessy]

Also could one of you more learned chaps comment on the 'less voltage for 4 ohm load issue'is it a function of the amp being required to deliver more current and the supply rails maxing out or what?

Not sure if I qualify for this 😉

But, without bothing to do the maths, I'd guess it's probably a combination of heat dissipation and SOA in the output devices.

With higher rails and lower impedances, there's a chance the Spike protection might kick in to protect the output devices and colour the sound.

Cheers,

Mark 😉

 

[Jared]

if I have an 8 ohm 80x2 amplifier that has a blown channel, what would a good guess on the transformer voltages be? any kathematics to get a ball park figure on this?

 

[mikelm]

if I have an 8 ohm 80x2 amplifier that has a blown channel, what would a good guess on the transformer voltages be? any kathematics to get a ball park figure on this?

It would not be suprising if a 2 x 80 watt amp had + & - 50 volt rails DC so if we assume no voltage regulators then the transformer AC voltage would be about 35V.

...but it's only a guess...😉


mike

 

[Jared]

bummer. so basically useless for a chip amp supply. I guess I might as well fix the nakamich receiver ! then..

 

[fedde]

With higher rails and lower impedances, there's a chance the Spike protection might kick in to protect the output devices and colour the sound.

Colour the sound ??? I'd say FUBAR the sound ! 😉

BTW: our Peter uses 22 Vac, but he said he measured around 37 Vdc !

Fedde

 

[MWP]

With higher rails and lower impedances, there's a chance the Spike protection might kick in to protect the output devices and colour the sound.

If it kicks in, youll hear it.... its not subtle.