Great deal on a 6 channel amp

by **scottw** on Fri Feb 23, 2007 1:24 am

Cool

How did you get it, off ebay??

by **summerall** on Fri Feb 23, 2007 1:39 am

I was able to get one from ebay the same "etom" guy. He shipped it quick!!!

Ok, now for the questions:

http://www.diymobileaudio.com/forum/sho ... php?t=8022

http://i6.photobucket.com/albums/y231/c ... 0_0138.jpg

I understand that each of the pins in the din cable is for a specific channel. But what are the switches for? Why did he add 2 switches and what do they allow him to do?

by **scottw** on Fri Feb 23, 2007 1:45 am

Sorry not really sure, I am not an electronics guru. I did not do anything special to mine but rig up the input cable, actually my father-in-law did the connections for me.
I am sure someone else will chime in here.

by **Marbles_00** on Fri Feb 23, 2007 2:35 am

I have to read the article again, but if I recall it was for instant combining of signals to specific inputs. He could have a discreete six channel amp to a "two" channel amp by switching in the proper config of switches.

Personally I like his final mod of placing the RCA's right in the amp housing and wiring to the SMT resistors. Very clean and slick indeed.

by **summerall** on Fri Feb 23, 2007 3:38 am

Some pics

http://www.retrojoystick.com/?page_id=18

by **summerall** on Fri Feb 23, 2007 3:49 am

So if I wanted to build this:

http://i6.photobucket.com/albums/y231/c ... 0_0138.jpg

Would I need 6 RCA connectors like this one?

http://www.partsexpress.com/pe/showdetl ... r=091-1203

by **Marbles_00** on Fri Feb 23, 2007 8:02 am

Well, maybe not just yellow. Yellow normally indicates a video connection...but hey, it's your build, you can do anything you want.

But yes, you'd need 6 rca type connectors. If your intentions are to have three stereo pairs, then use three red (right), and three white (left).

by **summerall** on Fri Feb 23, 2007 2:15 pm

What gauge wire do you recommend for connecting the din cable to the rca jacks?

by **summerall** on Fri Feb 23, 2007 9:27 pm

smata67 wrote:I just wanted to report back that I went ahead and made a connector to bypass the preamp altogether and the hiss is GONE. Since Etom sent me a replacement preamp and it too had the hiss, I'm guessing that it is just normal for that preamp. If you want to get rid of the hiss, bypass the preamp.

smata67 -

Would you happen to have any pics of connector you made? I am going to try to do the same thing this weekend.

by **Marbles_00** on Fri Feb 23, 2007 9:53 pm

What gauge wire do you recommend for connecting the din cable to the rca jacks?

You don't need a heavy duty wire, as your not carrying any current...remember it is a low voltage signal (typically no more then 2v p-p). The thing you want to remember is to keep the signal path as short as possible, or place within a shield braid to help keep unwanted signals from being induced on the lines.

Also remember, you don't have to cut the DIN connector. I linked a .pdf for a panel mount 6 pin mini-DIN to open ended fly-leads, in a previous post you may consider think of using. Dirt cheap and Digi-key has tons (if you in N.A.)

by **summerall** on Sat Feb 24, 2007 3:44 am

I have 20 gauge stranded and 22 gauge non stranded. I guess I'll use the 20 gauge wire.

EDIT - nevermind don't need the wire at all, just going to use the DIN cable's wire. BTW it is 26 gauge.

by **summerall** on Sat Feb 24, 2007 5:45 am

I finished the box. I'll probably make another one, this one was kind of a test. It sounds great, no hiss, no crackles and it allows my pc volume to be set lower. I'll build another one because the rca input jacks are aligned all that great and I probably could have soldered a little better.

http://www.retrojoystick.com/wp-content ... el-amp.jpg

http://www.retrojoystick.com/wp-content ... mp-011.jpg

http://www.retrojoystick.com/wp-content ... mp-012.jpg

http://www.retrojoystick.com/wp-content ... mp-013.jpg

http://www.retrojoystick.com/wp-content ... mp-014.jpg

EDIT - There is hissing when nothing is playing. Maybe because all rca jacks aren't grounded? I only grounded the first one (black wire). Do you think I should ground all?

by **Marbles_00** on Sat Feb 24, 2007 9:27 pm

What is your source? Computer? CD player?

What happens if you unplug the cable from the source? What happens if you unplug the cable from the breakout box? What happens when you unplug the cable from the amp?

Start by unpluging your source, does the noise dissapear? If so then your source is noisey.

If the noise is still there unplug the RCA's from the breakout box. If the noise goes away then your RCA are the source of the noise, otherwise then disconnect the DIN from the amp. If the noise is gone then it's the breakout box you have to contend with.

Otherwise, finally it is the amp that is creating the noise.

Most likely, if you are connected to the computer, it is computer noise your hearing.

by **sharp_1** on Sat Feb 24, 2007 9:35 pm

summerall wrote:EDIT - There is hissing when nothing is playing. Maybe because all rca jacks aren't grounded? I only grounded the first one (black wire). Do you think I should ground all?

If your box is plastic you must ground every RCA jack, if your box is aluminum you could get away without grounding but I would every RCA anyway.

by **samgreco** on Sun Feb 25, 2007 12:13 am

I found that in my house, which does not have true grounds in most outlets (built in the 50's), tha I needed to lift the ground on the amps. If I didn't, I got a HORRENDOUS BUZZ. As soon as I lifted the ground, it was as quiet as could be. All 4 (

) of the amps I bought were the same.

So, my mission, should I choose to accept it, which I will, is to run true grounds EVERYWHERE. Ugh.