TS9 Mods - Socket for Opamp testing

nick

Was feeling brave and adventurous today so I bought a RC4558P opamp and a socket at Mantech and fitted it. Quite chuffed with my soldering, looks factory ?

TS9 re-issue comes with a TA75558P so Ive been switching between it and the RC4558P and theres a definate difference in sound, asked for the JRC4558D which the original 808's came with but they didnt have stock.

Socket and two opamps.

I want to get a new JRC4558D and then try find a radio of sorts from the very early 80s and see if I can find a more vintage 'worn in' one and test them all back to back and see if there is a major difference.

Gearhead

Are you sure they will have stock again? It was my understanding the JRC4558D had been taken out of production...

nick

Gearhead wrote: Are you sure they will have stock again? It was my understanding the JRC4558D had been taken out of production...

Its back on the market it seems, a whole R4.20 for one. Just put the JRC op amp in and swopped two resistors in the output section and now the TS9 is apparently (according to the internet ?) 808 specs ?

nick

Two blue resistors are the ones I changed and the JRC chip in its socket

nick

Fitted a blue LED as the stock red one is far to dull

shadow1

NIce! whish i understood electronics more,i would love to mod like this....love the blue LED

matta

Gearhead wrote: Are you sure they will have stock again? It was my understanding the JRC4558D had been taken out of production...

Nope, it was NEVER taken off the market, a fable, due to the fact they were not easily available around the world, they did change the name through from JRC to NJRC, though the current NJRC chips are labeled as JRC.

Nick, yip that is stock 808 now... but it still will sound ALOT better with caps mods... all the 808 mod does is add more drive/gain in the output stage, with the 2 resistor changes, the opamp actually make VERY little difference, at least in comparison to cap changes/mods.

Cheers

Matt

nick

matta wrote:
Gearhead wrote: Are you sure they will have stock again? It was my understanding the JRC4558D had been taken out of production...
Nope, it was NEVER taken off the market, a fable, due to the fact they were not easily available around the world, they did change the name through from JRC to NJRC, though the current NJRC chips are labeled as JRC.

Nick, yip that is stock 808 now... but it still will sound ALOT better with caps mods... all the 808 mod does is add more drive/gain in the output stage, with the 2 resistor changes, the opamp actually make VERY little difference, at least in comparison to cap changes/mods.

Cheers

Matt

This is probably as far as my fiddling expertise goes, I'll leave the tricky bits up to you when I find a chance to pop round ?

nick

So apparently Im getting better at this! Tried to get WIMA caps but Mantech and Communica said they didnt have, Mantech only had 0.1uF in stock.

nick

The modded tubescreamer is light years ahead of a stock, with the cap changed to allow more bass through its waayy better. The opamp barely makes must difference to my ears, Ive played all 3 and there is slight difference but nothing to get overly excited about (but I did stick with the JRC one). The tone cap mods just bring it to life though! 8)

FenderBender

Nicely done Nick!

RS carry a massive range of caps http://za.rs-online.com/web/search/searchBrowseAction.html?method=browseSuperSection&N=4294963308#Capacitors

I use them for all the stuff that Mantech and Yebo don't have.

brownsounds

Hello, Where can I get the plans to try and do these mods myself. Cheers

nick

brownsounds wrote: Hello, Where can I get the plans to try and do these mods myself. Cheers

There are tons of websites out there for this. To do the 808 mod I used: http://www.tonepad.com/photoessay.asp?photoEssayID=9