Looking for Amp project suitable for a 35V and 15V Transformers?

[bezobraznia]

I have 400W transformer 11.8V-5V-0-5V-11.8V AC
And i want to ask for some power maybe SE amp for this voltage... I'm made DoZ, and i experiment with this trasnformer, but voltage is so small for correct sound.
Please give me some amplifier ideia for this transformer..
....
Second question is that i have almost 1Kw transformer, but with 7.5-0-7.5 ... what about sheme for amplifier with this transformer?
...
I preffer Class A etc...

Thank you in advice...
Best reggards! / Niki / Bulgaria

[sam9]

Those are pretty odd sizes. To get much use out of either the first thing to investigate is a voltage doubler. For the second one a voltage trippler. I suggest you solve those problems first since the voltages quotes 11.8V and 7.5V are too low to do much in audio except preamps, headphone amps, and signal processing of one kind or another. And for those uses the wattage/VA rating are way more than you need.

I would say the second transformer with a voltage doubler could be used for a moderate (30W?) class A amp. The 1kW rating may even allow you to drive 4 or 5 amps, in case surrouind sound interests you.

The first one doubled might do for a stereo 30W or so class A.

But before you commit to a particulasr amplifier project, checkout voltage doublers & tripplers and decide if that is something you want to consider. When you know the rail voltages you will have available it will be easier for people here to suggest an amp project.

Maybe someone else here has a better idea.

[Greg Erskine]

Originally posted by bezobraznia
II'm made DoZ, and i experiment with this trasnformer, but voltage is so small for correct sound.

I would have thought using 11.8 and -11.8 giving 23.6 volts would have worked OK for the DOZ. I was intending to use a 12-0-12 volt toriod for a DOZ after Rod said it should be OK.

What rectifier are you using and what is your DC voltage?

BTW: I run various LM1875 and LM3875 GCs from a 12-0-12 300VAC toriod and they work OK.

[serosmaness]

How about this amp.
Easy to build.
JLH 10 Watt class A amplifier


Serosmaness

[paulb]

If you end up using a voltage doubler (or tripler), you might want to use a capacitance multiplier to help with filtering, because the ripple voltage from a multiplier circuit is very high.
There is a suitable circuit at www.sound.au.com

[MikeW]

Build a Le Monstre.

[bezobraznia]

Thank You for Your replyes...
I consider that i don't want doubler or tripler
I have already DoZ and i want another chalenge for me
DoZ is ok with more voltage - above 40V...I'm not a fan of Capacitance Multipler , I preffer big capacitance (abouve 100mF) and riple filter on AC voltage before transformer..
I will think about LM1875... hm... i will experiment with low power voltage for LM3875 - i have four of these... but i think that for 4 or 5 channels home theatre lm1875 will be ok with 7,5-0-7,5 (1kw) transformer...
About JLH- I want more than 10W... soon i will build SE (or maybe push-pull) with 2xEL34+ECC83 and this will be my low Watt-age amp
What kind amp is this Le Monster?!
Best Reggards!
Niki / Bulgaria

[bezobraznia]

Hello I have importand corection about second 7.5-0-7.5 transformer
It is not voltage above, but correct voltage is:
Two independant windings with
15-0-15 AC (but with so thin wire)
and importand is 10-0-10 AC - hard wire!
...
And i see Le Monstre... good design , but now i know - I want Class A SE with this transformer
...
and the trasnformer is not 1kW but - onli 400-500W
...
sorry for annoyances about scales...

Best Reggards

[johnthetweeker]

I would rather get a transformer made for the amp than the other way round! I do not know about Bulgaria, but here in India I can get just about any transformer made to specification quite easily.

John.

[sam9]

You can get them custom made about anywhere -- thr question is -- at what cost?