New Amplifier 95% done-what do you think?

[zox2003]

Here is picture of my new amp that I 95% completed.Tell me what do you think about Amp.
It is 2 X 120W on 4 ohms.
Input: MPSA56
Pre-Driver Stage: TIP31C and TIP32C
Drivers:MJ15034 and MJ15035
Output: MJ15003 and MJ15004


Thanks...

 

[hienrich]

wow!



pretty well done ....

what are those relays for? inrush current protector? or speaker output
relays?

pls. attached schematics as well.

nice work there@#$%^&*(......

regards,

hienrich

 

[zox2003]

relays

They are Speaker Output Relays !!!

 

[bvp9223]

Nice work, zox.
I'm just curious that how your pcbs are made by and their dimensions.

BvP

 

[jkraxi]

and the schematics?

 

[zox2003]

PCB adn Dimensions

I made PCB my self.Dimensions of PCb are 7.5 x 6 inch.
Schematic is coming soon.

 

[EWorkshop1708]

Very nice.

What size caps are those? They look large.

 

[zox2003]

Capacitors

Caps are 10000uF /63V.

 

[hienrich]

zox

what about your shemes aren't you gonna show them.

it's interesting, and ya sonic quality tell us more of it..

regards,

hienrich

 

[zox2003]

Schematic-Working

Here is "working" schematic.I did not have time to make schematic in OrCAD but I will do it next week.

TELL ME WHAT DO YOU THINK ABOUT IT.
WORKS VERY GOOD.I AM DOING SOME MEASURINGS RIGHT NOW.

Regards,

Zox

 

[zox2003]

Wrong marking Transistor

I am sorry.I marked transistor wrong on schematic.
MJ15005 is actually MJ15004.

Thanks

 

[hienrich]

try bd139 on the VBE multiplier.

and try bc556 on the diff amp.

and notice sonic changes.

I'm using the same circuit topology for my subs,

simple, yes but awsome...

regards,

hienrich

"nice work there"

 

[hienrich]

zox,

take a look at this,

it a word doc and I accidentally inverted it...

and its a quasi_complementary design a close neighbor to yours..

don't be confuse...

regards,

hienrich

 

[MikeB]

zox,
if you try different inputtransistors, don't forget to test the 2n5401
and get surprised...
In one of my amps i replaced bc546/556 with 2n5401/5551, and
was a bit shocked over the improvement !

Mike

 

[thanh]

hi zox! how is the vbias of vas ,the voltage between collector(MPSA06) and V-?
with the value that is show in this picture, my amp could work but not good

 

[hienrich]

I agree with MikeB



yes a pair of 2n5401 is also better.......

regards,

hienrich

 

[Upupa Epops]

To Mike : Explanation ?

 

[MikeB]

Hi Upupa !

Yes, i know, the specs of the 2n5401 are not impressive, but for
some reason devices with lower hfe seem to be better choice
for voltagegaindevices.
In sims i observed some dynamic phasehift at the base of these
devices, bc556 showed it very heavy, nearly all transistors, but
jfets don't, and... 2n5401 ! (phasehift inside audioband)
Sounds like a farytale...

Mike

 

[Upupa Epops]

To Mike : Try it simulate with higher value of serial resistor in base circuit ( 1 k ? ) instead normal value ( 47 - 100 R ), but with normal BC's. I mean that it is caused by lower beta of 2 N.... transistors ( than normal BC's ) and by lower OLG of amp.

 

[thanh]

Try it simulate with higher value of serial resistor in base circuit ( 1 k ? ) instead normal value ( 47 - 100 R

Hi Upupa! Do you meant "the stop resistor" of base of diff transistor?
perheps you will give me a good news!