CurtPalme.com Home Theater Forum

dvh99 · Joined: 25 Dec 2009 Posts: 2158 Location: nederland

donations are welcome i have the details for those that are interested.
i had a chat with mike and he is willing to mod the 03p vim.
mais je n`ai pas l`argent c`est dommage.

GeorgeSong · Joined: 31 Oct 2008 Posts: 74 Location: Canton,China

i have 3 pics of VIMS:
2005-03P
2035-02P
2035-03P

dvh99 · Joined: 25 Dec 2009 Posts: 2158 Location: nederland

????

jantje112 · Joined: 17 Jul 2006 Posts: 328

I have a spare 2035-03p vim, badly enough it's not working anymore. Maybe I let it get fixed and modded, should be fun!

dvh99 · Joined: 25 Dec 2009 Posts: 2158 Location: nederland

looking at the schematic it must be possible to place the ad834 instead of the ad835 and from there on use an addon board for the 2n3906 transistors to be used.
pins 4 and 5 should go to the addon board amplified and then fed into the clc449.
you will need +5v and -5v as well.
if i have a spare 02p vim this is a fun project.

dvh99 · Joined: 25 Dec 2009 Posts: 2158 Location: nederland

the 02p and 03p vims use the same circuit except the end section.
jarmo is going to send me a few pcbs.
i am going to order some parts for the addon board.
if all works well this will be a cheap upgrade for everyone owning a 02p vim.
jarmo tried some other transistors but had problems with them and used the 2n3906 as in the schematics, i will try some other with about the same specs as the 2n3906.
i was looking at a replacement for the clc449 and found these (link) what do the experts here "wink wink" tse think about the replacement for the clc449.
little diode charges 20 bucks a piece on ebay and since the ad834 don`t come cheap i wasnt planning on spending another 60 dollars on the clc449s.

http://www.farnell.com/datasheets/53391.pdf

if i use these do i have to replace the clc449 on the vnb`s too?

dvh99 · Joined: 25 Dec 2009 Posts: 2158 Location: nederland

http://www.vishay.com/docs/70228/70228.pdf

this is a mosfet i want to try instead of the 2n3906.
someone knows if this will work.
i am still making an inventory of what i need before ordering.

tse · Joined: 03 May 2006 Posts: 1014 Location: Sweatbucket, Fl.

The THS3201 should be a good replacement for the CLC449. It isn't a drop in replacement. With the gain set for +2 and +/- 5V power the feedback resistor for CLC449 is 250 ohms. For THS3201 it needs to be 715 ohms. The gain set resistor will have to change, also.

I am not going to say that the mosfets won't work. They might but I have to question the on resistance. At 300 ohms it is kinda high for the circuit. It will be plenty difficult to make the circuit work as designed by Analog Devices. Good RF circuit board design will be needed.

Scott

dvh99 · Joined: 25 Dec 2009 Posts: 2158 Location: nederland

scott on the 02p they use 260 ohm and on the 03p 300 ohm.
why the difference?
thanks btw i appreciate your input.
which traces need to be kept as short as possible?
is it wise to use 3 different ground planes for the 3 colours?

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

Scott, The transistors Dennis is talking about are after the Ad834 . They have a 20 ohm resistor before or after it IIRC. I'm going by Memory here. He is not talking about the op Amps.
The Op Amps you mention I did try and got to work somewhat with the spec'd resistors for FB and G and then the DC restore resistor as well but it did Oscillate a lot. I think If i had a vari Cap in parallel on the R92 or R83 i might have been able ti find the right combination. Jarmo tried it as well and lots of different buffering caps on the supply rails. But I think caps on the FB Or FG resistors would work too. I still want to get back to those some day, as they were razor sharp on the old 2006-03p vim but were Bright as Hell!!!!!!

Just looked they are in location Q18,Q19 Red Channel

Athanasios

dvh99 · Joined: 25 Dec 2009 Posts: 2158 Location: nederland

i will be ordering resistors in the range of 200 till 1k 1% for testing.
for the buffering caps i try 0.1 0.47 1 10 and 22uf.

i will use 1% resistors all along this circuit and maybe some with even a better tolerance for feedback and gain.
cannot wait to receive the boards from jarmo.

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

Dennis here is what jarmo did on the Decoupling caps for the THS 3201.

mp20748 · Posted: Mon Aug 09, 2010 2:10 am Post subject:

How did he get a 3201 to work with those FB/G resistors?

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

Thats what I don't know, the stock resistor will no way work. I used 750 as they were all i had and I got close but gave up when i messed up the protection circuit accidentally on that vim. He said he had it working but went to the El5166 after for some reason.

Athanasios

1031 · Joined: 22 Mar 2006 Posts: 657 Location: Finland

1031 · Joined: 22 Mar 2006 Posts: 657 Location: Finland

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

tse · Joined: 03 May 2006 Posts: 1014 Location: Sweatbucket, Fl.

Pics of a prototype board using the AD834. I can't believe that was in 2004. Wow!

Scott

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

I love CRT nostalgia ! Wink

Athanasios

dvh99 · Joined: 25 Dec 2009 Posts: 2158 Location: nederland

yeah that is one cool picture there scott.
jarmo too bad your holiday has finished i hope you had a great time, where did you spend your holiday, italy spain greek islands?
i will defenitely try that ths3201 even if it takes me 20 decoupling caps Smile

.
as for the transistor/mosfet i have been searching some more on the www and i found this
http://www.semiconductor-sanyo.com/ds_e/ENN3179A.pdf
if anyone has some suggestions for a replacement for the 2n3906 please let me know because i am still on the lookout.
the 2n3906 is a limiting factor and i do not want that.