A60(+) Amplifier. Build this?

[Paroxod4]

I looked at the A60 today, there are 2.2 ohm resistors in the transistor bases.

 

[Paroxod4]

Hey Berlusconi, where are you, help me, otherwise my head is spinning.

 

[Berlusconi]

Hey Berlusconi, where are you

I'm glad to hear from you my dear friend.
As usual, at the end of year I work at the double speed, but from today untill Januarry 8th I will have vacations, as I do every year.
Lets have some fun here.

 

[Paroxod4]

My friend, don’t be distracted by my questions. Have fun during the holidays. Have a nice New Year holidays. Guys, I’m glad I have you.

 

[Radian]

Yes community effort is fun and gives a sense of family atmosphere 😎
On top of that we are climbing the ladder of high fidelity.

Cheers Klaus

 

[Radian]

Got a bunch of 24v ac single winding transformers. Will these work with the A60?
+ (-+) - of course.

 

[Paroxod4]

24x1.4 = 33.6V amplifier power supply, for sensitive acoustics there may be enough power. In the description from 24V to 42V.And yet, who is free from holidays, how do base resistors affect and what is best to do? Leave it at 11 ohm, or replace it with 2.2 ohm or 10 ohm?

 

[Radian]

Ok checked output with no load 30.4V ac
I don't know how much the voltage will drop after a load is applied.

 

[Paroxod4]

What is the power of the transformer? Post the size and photo. Maybe you have all the data?

 

[Radian]

 

[Paroxod4]

The transformer is good. It’s not clear how many windings there are for 27.5V? The amplifier needs 2 windings of 27.5V, or one 55V with a tap from the middle. For double mono you need either 2 of these, or one with double the power and a bunch of windings. Read at the beginning of the topic, all these issues were resolved there.If you have one winding, then this will not work.

 

[Radian]

Single secondary coil. I will be using 2 transformers per channel
(27v+) (27v-27v+) (27v-)

 

[Paroxod4]

I wrote to you. You need 2x27V or one 55V but with a lead from the middle. Scheme 27-0-27.4 transformers per amplifier? That's cool.

 

[vmk2002]

Good transformer. 4 pieces will have a decent weight. Do not forget that you also need a voltage of 12VAC for the protection circuit. Well, 4 transformers of such power need to be launched through a soft start.

 

[Paroxod4]

I assume that there will be monoblocks, each in its own case? Then 2 transformers in one is normal, but not practical. Why not sell 4 pieces and buy one if there is only one body?

 

[Paroxod4]

Fresh Toshiba transistors arrived for a new project. I just ordered something small, I need 16 pairs.

 

[Radian]

Good transformer. 4 pieces will have a decent weight. Do not forget that you also need a voltage of 12VAC for the protection circuit. Well, 4 transformers of such power need to be launched through a soft start.

I will use them with LT4320 models so single winding is actually a demand not a problem.
Can you recommend a soft start module?

 

[Paroxod4]

When I remade the A60 without a volume control, the question of soft start also arose, everything was in the kit. I decided not to buy, I have a lot of parts in stock. I did it myself in one evening. It works perfectly, without additional power.

 

[Radian]

Thanks I will check my parts bin.

 

[Paroxod4]

I don’t know how to send you a printed circuit board to LAY.This one is the same, but for some reason the powerful resistors are not shown. I think you’ll figure it out.