Very simple: I just want to add RCA inputs to my SI T-amp

[Naga]

Is this a strait swap and solder? or are there some issues with the grounding?

 

[pne]

its a swap, will you be using the original case?

 

[mono]

It's a straight swap to the extent that it will work if you remove the minijack to do it. The minijack is a shorting type that grounds out the inputs when there isn't a plug in it, so if you were to simply tack some jumper wires onto the bottom of the PCB that went to the RCA inputs, without removing the minijack from the PCB, you would need to keep a dummy plug in the minijack to keep the inputs from grounding out.

 

[rellik]

is that because the amp would go crazy with no input?

im planning on modding mine as well

 

[mono]

No it won't go crazy, I just unplugged the RCAs on mine and heard nothing. It takes them practically no time to do it and negligable cost though, so they did.

 

[Naga]

Quote:

Originally Posted by mono It's a straight swap to the extent that it will work if you remove the minijack to do it. The minijack is a shorting type that grounds out the inputs when there isn't a plug in it, so if you were to simply tack some jumper wires onto the bottom of the PCB that went to the RCA inputs, without removing the minijack from the PCB, you would need to keep a dummy plug in the minijack to keep the inputs from grounding out.

ok, ill do this then

rid myself of the crappy miniature plug ( i hate mini plugs )

solder in a pair of rca jacks ( common ground ? )

 

[mono]

Yes the input has a common ground but the speaker output does not.

 

[Lavalamp]

I recently modded mine.

I found these useful:

http://www.tnt-audio.com/clinica/t-amp_tweaks_e.html

http://www.michael.mardis.com/

I should say that on my model, the TNT instructions were wrong about being able to leave the input jack on the board, and just solder your inputs to the bottom. The jack on my unit had a switch. I had to remove my jack completely, which took some patience as the board is quite delicate.

 

[Naga]

thats awesome! ill look into these mods shortly

 

[gychang]

Quote:

Originally Posted by Naga Is this a strait swap and solder? or are there some issues with the grounding?

I will be putting in a new case and change to RCA input but need to have more than one input.

what part do I need? (I am a newbie but can solder, website-page in US will be great).

thanks,

gychang

 

[mono]

Quote:

Originally Posted by gychang I will be putting in a new case and change to RCA input but need to have more than one input. what part do I need? (I am a newbie but can solder, website-page in US will be great).

The easiest way would be to use a dual-pole, multi-throw switch. For example, if you have 3 inputs the switch might be noted as DP3T, or 2P3T. One pair of contacts is common, connected to any of the other sets when you move the switch so that pair goes to the SI input. The other pairs of switched contacts go to each RCA input. Each pair has left and right for each channel and then the grounding is common. If you can't use common grounding then a 3 pole, 3P(n)T switch instead.

Typically more than 2 (sometimes 3) throws would be a rotary switch while lever types are most often 2 throws.

 

[gychang]

Quote:

Originally Posted by mono The easiest way would be to use a dual-pole, multi-throw switch. For example, if you have 3 inputs the switch might be noted as DP3T, or 2P3T. One pair of contacts is common, connected to any of the other sets when you move the switch so that pair goes to the SI input. The other pairs of switched contacts go to each RCA input. Each pair has left and right for each channel and then the grounding is common. If you can't use common grounding then a 3 pole, 3P(n)T switch instead. Typically more than 2 (sometimes 3) throws would be a rotary switch while lever types are most often 2 throws.

can u do me a big favor and find the part at

https://www.allelectronics.com/index.html

I am not sure which part to order.

thanks,

gychang

 

[mono]

Quote:

Originally Posted by gychang can u do me a big favor and find the part at https://www.allelectronics.com/index.html I am not sure which part to order. thanks, gychang

You still haven't described exactly what you want to do, like, how many channels you want or "need".

Here's one, 4P3T that'll allow switching 3 pairs of inputs and their grounds too (If desired). It may not be the highest quality (or might be fine, I don't have one) but personally I prefer closed switches as they seem to stay cleaner over time.

Link

Miniature Toggles Examples

Standard Toggles

Remember that you need one with at least 2P (poles) and 2T (throws) just to switch between two stereo inputs, then add one (3P) to switch ground too, and add one (3T+) for each addt'l input (Pair of RCA jacks). So for example if you wanted a hypothetical switch that switches 3 wires (Left, Right, and Ground) between 4 pairs of inputs, it would be 3P 4T, or more (P)oles and (T)hrows and you'd just leave the unneeded ones, unused. Often when switches have only 1 or 2 poles or throws they'll list (S)ingle or (D)ual instead of 1 or 2.

Beyond that, it may be personal preference if size, lever/button/whatever type, cost, etc.

Sometimes I am leery of buying switches from surplus 'sites because the contacts are tarnished from old age or bad environment/storage. Those can be cleaned off easily enough but when I see the external contacts tarnished, I wonder about the internal contacts too and end up opening up the switch (which can be a bit like microsurgery, especially getting it back together if a spring-loaded toggle type), and polish the contacts with a dry cotton swab (or in worse cases, I put brasso on a cotton swab but let it dry completely before using it so it is less abrasive and makes minimal mess).

These are only workarounds though, if you are buying other new parts from another primary parts supplier, I'd get the switch there instead of a surplus 'site. Don't get me wrong, I've bought switches from Allelectronics and other places that were fine, but I've also bought some that weren't and needed cleaned.

 

[gychang]

Quote:

Originally Posted by mono You still haven't described exactly what you want to do, like, how many channels you want or "need". Remember that you need one with at least 2P (poles) and 2T (throws) just to switch between two stereo inputs, then add one (3P) to switch ground too, and add one (3T+) for each addt'l input (Pair of RCA jacks). So for

thanks for the input for this newbie.

I need to switch between CD and ipod input to t-amp (2 RCA jacks), will have no ground (only 2 prong AC switch).

http://www.action-electronics.com/gcswrot.htm

the part number "#35-378" work?, I will just have one extra input not being used?

gychang

 

[mono]

Yes, "#35-378" works