| 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? |
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| 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. |
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| Nuuk |
| quote: | | 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. |
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| 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? |
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| mhennessy |
| quote: | Originally posted by mothman
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 ;) |
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| 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? |
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| mikelm |
| quote: | Originally posted by 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? |
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 |
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| Jared |
| bummer. so basically useless for a chip amp supply. I guess I might as well fix the nakamich receiver ! then.. |
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| fedde |
| quote: | Originally posted by mhennessy
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 |
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| MWP |
| quote: | Originally posted by mhennessy
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.
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If it kicks in, youll hear it.... its not subtle. |
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