70V line transformer: step down 70V to 16 ohm
green
http://www.horrorseek.com/home/halloween/wolfstone/Audio/spk70v_LineTransformer.jpg
Before, I have set up this transformer behind a regular 4/8-ohm
amplifier to drive 70V speakers.
Instead, I would now like to run a 8- or 16-ohm channel using a 70V
out on an amplifier. So from the 70V amplifier (TOA DA-250FH) output
to the terminals marked "OUTPUT 70V LINE", then out from the terminals
marked "INPUT 4 OHM" to a channel of either 8 or 16 ohms. I do not
intend this to be for normal usage, but in an emergency if my regular
amplifier fails. Is this safe; will it work? Will the wattage be
reduced significantly? What if I overdrive the transformer?
Thanks lots.
Phil Allison
"green"
>
>I have a transformer like this:
> http://www.horrorseek.com/home/halloween/wolfstone/Audio/spk70v_LineTransformer.jpg
>
> Before, I have set up this transformer behind a regular 4/8-ohm
> amplifier to drive 70V speakers.
>
> Instead, I would now like to run a 8- or 16-ohm channel using a 70V
> out on an amplifier. So from the 70V amplifier (TOA DA-250FH) output
> to the terminals marked "OUTPUT 70V LINE", then out from the terminals
> marked "INPUT 4 OHM" to a channel of either 8 or 16 ohms. I do not
> intend this to be for normal usage, but in an emergency if my regular
> amplifier fails. Is this safe; will it work?
** Should be fine.
> Will the wattage be reduced significantly?
** With a 4 ohm speaker you will get around 100W max, 50W with 8ohms and
25W with 16 ohms.
What if I overdrive the transformer?
** Only possible at low frequencies .
Do not use for bass guitar.
..... Phil
green
> "green"
> > Is this safe; will it work?
>
> ** Should be fine.
Excellent; thanks.
> > Will the wattage be reduced significantly?
>
> ** With a 4 ohm speaker you will get around 100W max, 50W with 8ohms and
> 25W with 16 ohms.
Okay. With this assurance that I will not be breaking anything, I can
go ahead and test it later.
> What if I overdrive the transformer?
>
> ** Only possible at low frequencies .
>
> Do not use for bass guitar.
Okay, that should not be a problem. Speech only.
Thanks.
bob urz
In most situations, i would say yes. But there are a few issues here
i think i would contact TOA customer support and ask.
That amp is a relatively new Digital class D amp. Not a conventional
class B. It may or may not be unstable into that transformer. I would
ask TOA.
The DA-250Fh has a 250watt 70 volt output
> http://www.toaelectronics.com/amp0012.asp
This is a high Z output NOT TRANSFORMER ISOLATED!
There is a optional 70volt iso transformer the MT-251H.
your radio shack transformer has a 100watt rating
> http://support.radioshack.com/support_audio/doc16/16226.htm
So, your driving a 250 watt output into a 100 watt rated transformer.
The turns ratio and the amount of core and copper is going to be
different in a transformer rated for 250W.
Lightly loaded at low levels, you may be OK.
Run it full bore at a low Z load and i smell a possible fried digital
amplifier that may not be warrantied by TOA if you tell them what you did.
Toa does have a output transformer they use for similar models the MT-450M
bob
bob urz
In most situations, i would say yes. But there are a few issues here
i think i would contact TOA customer support and ask.
That amp is a relatively new Digital class D amp. Not a conventional
class B. It may or may not be unstable into that transformer. I would
ask TOA.
The DA-250Fh has a 250watt 70 volt output
> http://www.toaelectronics.com/amp0012.asp
This is a high Z output NOT TRANSFORMER ISOLATED!
There is a optional 70volt iso transfomer the MT-251H.
your radio shack transformer has a 100watt rating
> http://support.radioshack.com/support_audio/doc16/16226.htm
So, your driving a 250 watt output into a 100 watt rated transformer.
The turns ratio and the amount of core and copper is going to be
different in a transformer rated for 250W.
Lightly loaded at low levels, you may be OK.
Run it full bore at a low Z load and i smell a possible fried digital
amplifier that may not be warrantied by TOA if you tell them what you did.
bob
Phil Allison
"bob urz is a complete FUCKWIT "
> That amp is a relatively new Digital class D amp. Not a conventional class
> B. It may or may not be unstable into that transformer. I would ask TOA.
** But YOU would be an idiot and a pathetic old fool.
The amp is DESIGNED to drive 70 volt transformers !!!!
The ONLY things it is ever intended to drive is fucking 70 volt
transformers.
----------------------------------------------------------------------------------------
> your radio shack transformer has a 100watt rating
>
>> http://support.radioshack.com/support_audio/doc16/16226.htm
>
>
> So, your driving a 250 watt output into a 100 watt rated transformer.
** ROTFL !!
70 volts is 70 volts - it does NOT matter what rating transformer you
connect as long at it accepts 70 volts.
> The turns ratio and the amount of core and copper is going to be different
> in a transformer rated for 250W.
** So fucking what ??
You can connect a single, 2 watt 70V tranny if you like - or up to 125 of
them.
What a fucking IDIOT you are - Bub Errs.
> Lightly loaded at low levels, you may be OK.
> Run it full bore at a low Z load and i smell a possible fried digital
> amplifier that may not be warrantied by TOA if you tell them what you did.
** This is the stupidest possible advice.
Bub Errs thinks he is an expert ( LOL)
- but in reality, the cunt is a demented, autistic retard and an
incorrigible public menace.
..... Phil
Phil Allison
"bob urz is a complete FUCKWIT "
> That amp is a relatively new Digital class D amp. Not a conventional class
> B. It may or may not be unstable into that transformer. I would ask TOA.
** But then YOU would be an idiot and a pathetic old fool.
The amp is DESIGNED to drive 70 volt transformers !!!!
The ONLY things it is ever intended to drive is fucking 70 volt
transformers !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
----------------------------------------------------------------------
> your radio shack transformer has a 100watt rating
>
>> http://support.radioshack.com/support_audio/doc16/16226.htm
>
>
> So, your driving a 250 watt output into a 100 watt rated transformer.
** ROTFL !!
70 volts is 70 volts - it does NOT matter what rating transformer you
connect as long at it accepts 70 volts.
> The turns ratio and the amount of core and copper is going to be different
> in a transformer rated for 250W.
** So fucking what ??
You can connect a single, 2 watt 70V tranny if you like - or up to 125 of
them.
What a fucking IDIOT you are - Bub Errs.
> Lightly loaded at low levels, you may be OK.
> Run it full bore at a low Z load and i smell a possible fried digital
> amplifier that may not be warrantied by TOA if you tell them what you did.
** This is the stupidest possible advice.
Bub Errs thinks he is an expert ( LOL) but in reality,
the lying cunt is a demented, autistic retard and an
green
Phil, a calm discussion would be great, otherwise I can look for
information elsewhere.
Phil Allison
"green"
> Thanks for your first post, Phil. Thanks for your post, Bob.
>
> Phil, a calm discussion would be great, otherwise I can look for
> information elsewhere.
** Then go.
Cos I am not letting up on trouble making, lunatics like Bub.
... Phil