bridging amplifier with input transformers

[muddasirwaheedmalik]

Hi,


I have 2 , YAMAHA B-5 POWER AMPS, each rated at 200W/Ch into 8 ohm, my aim is to bridge to make them monoblocks for 8 ohm speakers.

The objective is to get better CMMR and not higher output power , so i want to use an output transformer 2:1 step down , any idea how to implement it?

Is step down ratio correct ?
Should i use split input transformer?
How to implement it to get better sound quality , like the one implemented by McIntosh.

Regards

[Osvaldo de Banfield]

A transformer for high quality for this power will be a monster. Definitively not needed.

[muddasirwaheedmalik]

what about input transformer? any implementations link/sugggestion ?

[muddasirwaheedmalik]

and BTW i wanted to implement OPT to increase load impedance as 8 ohm would be 4 ohm in bridge and i donot want to push high currents through the amp.
I will be fine with lesser available power but greater SQ and damping factor?

[Osvaldo de Banfield]

It is unnecessary. Simply reduce input signal. And a inverter can be done with a single transistor and few resistors, or a opamp. There are lots of circuits that don´t need a transformer. The Xformer is a source of lots of problems, so though the time has been searched forms to avoid it.

[owenhamburg]

Using a transformer can safely isolate the electrical input.

I wonder if a transformer on the input might remove some noise from a computer power supply? Im looking at building some balanced inputs, and playing.

This is more a subject for line level pre-amps though.

[Osvaldo de Banfield]

Originally Posted by owenhamburg

Using a transformer can safely isolate the electrical input.

I wonder if a transformer on the input might remove some noise from a computer power supply? Im looking at building some balanced inputs, and playing.

This is more a subject for line level pre-amps though.

It may be done more easily with a photocoupler, and getting ouput from emmiter for one channel, and from collector to the other, lower cost, lower space, lower hum, lower....

[muddasirwaheedmalik]

here is the issue, a P-2 Statement Anthem amplifier is aroung 2500 USD, i have 2 Yamaha B5 amplifier, built like tank, even the screws are made of copper, which is 200 W/pc into 8 ohm so i wanted to make a 400 W/pc monoblocks into 8 ohm so as no to push the current limits of an old ampliifer , since the 8 ohm in bridged would be 4 ohm for which there is no rating mentioned for amplifier i need to increase the load impedance at least to 8 ohm to get around 400W monoblocks which are way cheaper i.e. 300 USD/piece (my purchase ) , better SNR. better CMMR and hopefully better SQ ???? any suggestions,

BTW the heat sinks on Statement Anthem P2 indicates a very low bias current for power output of 350 Wpc , which means lower B region amplification, whereas the generous heat sinks of yamaha means higher bias and more towards class AB amplification ??


any ideas ?