Upgrading Sun Audio 2A3 amplifier

[srinisundar]

Long time i am thinking of doing modification of my Sun Audio replica 2A3 amplifier bought from Hongkong.

Time has come now and with the help of Mr.Rajkumar who is an graduate electronics engineer and also doing amplifiers for home use and for music instruments.

Sourced parts from Parts connexion and tube depot, hope the pictures speak of the components changed.

Day night change is visible once the PIO capacitors were changed and smoothness in voice is very audible and an novice also can tell the same.

Anybody want to have an demo of the same, warm welcome to my home.

2A3 internal before modification: https://ibb.co/jRASJw

Components changed:

I have changed the OPT's ( 2 no's) also which is Hammond 125ESE. ( https://ibb.co/m1gmTw
https://ibb.co/jKy0ow

Few pics during mod.

https://ibb.co/cpfPFb
[url]https://ibb.co/jWst8w[/url]
[url]https://ibb.co/eXFD8w[/url]
[url]https://ibb.co/c0Frvb[/url]
[url]https://ibb.co/dParvb[/url]
[url]https://ibb.co/jBZUgG[/url]
https://ibb.co/fNdBvb

Pic after mod : https://ibb.co/i441vb

If need any technical clarification, i will answer to an certain extent, or else will ask Rajkumar to post here for further detailed queries.

With wishes

Srini

 

[sann]

K40y-9 are wonderful capacitors and at the same time very reliable, they dont leak as some other oilers tend to over time.

PIOs bring out that vintage charm especially when used with vlaves and Altecs
Try Belden 8402 IC's if you have not already.

Regards,
sann

 

[Beast_of_burden]

Cool. I would love to build a kit like that. How did you source it? Is it possible to order a kit without the OPTs and tubes? I need the case and the PCB + components.

 

[srinisundar]

i have bought as built amplifier from HK and upgraded now since parts used were of cheap one's . However the built amp is worth for the price and now that most of the mod's were implemented it is sounding very good.

However please be in in touch with our forum member, ragu and he will be helpful to you. ( http://www.hifivision.com/members/nraghunadh.html )

Regards

 

[radium7]

This amp have Chinese metal film resistors and capacitors and the output stage cathode resistor also very poor. The OPT used in the amp have only 2 primary and 2 secondary sections but didn't have proper insulation between each layer and not seems to be good enough for a Hifi AMP. we decided to replace all resistors and capacitors and the OPT.

Metal film Resistors replaced with TAKMAN carbon film resistors (Non inductive and Non magnetic).

Output stage cathode resistor from REIDON resistors

Cathode bypass capacitors replaced with Elna (cerafine) capacitors

Power Capacitors replaced with F&T Dual Radial Capacitors

The Coupling Capacitors are the famous Russian PIO Capacitors.

OPT replaced with Hammond transformer.

 

[srinisundar]

Thanks Raj for your clear indications about the. Components replaced.

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