manix1979 Posted March 12, 2017 Share Posted March 12, 2017 Hi! I have a question: I'd like to place the guitar input jack at the back of the amp head. Best solution would be a 2nd jack at the back. I opened the amp head allready for cleaning and tried to solder a guitar jack on the input jack. No success... drilling for the back hole is no problem, soldering as well no problem. But how to solder it to make it possible? The original jack is a pcb jack with 6 connectors. No idea about the polarity... is it a trs jack or not? I have a trs guitar jack and a mono jack here. What connectors of these 6 should i use to get it working? Greetings from Austria Quote Link to comment Share on other sites More sharing options...
spaceatl Posted March 15, 2017 Share Posted March 15, 2017 You only need a twisted pair of wire. As far as which pins, you just need to measure a bit....plug a 1/4 cable in the jack and use a multimeter to find the pin for the tip and the sleeve...run it to the back jack....But make sure that you use a twisted pair...Probably don't need a shield inside the box but you could use one if you want...twisting the pair is much more important. you can test it with a multimeter when you are done...plug a 1/4 cord into each jack and multimeter tip to tip and sleeve to sleeve and make sure you don't have a short. A TRS jack is better structurally...you just tie the sleeve and ring together and you get a firmer jack for the plug. You don't have to use one but it's just helps the plug sit in the jack a little tighter. Quote Link to comment Share on other sites More sharing options...
manix1979 Posted March 15, 2017 Author Share Posted March 15, 2017 Thanks for your help. As far as you told me I were allready ;-) Get no signal on the multimeter... wether the multimeter is damaged or I made a mistake. I'm not new to soldering, volts and polarity... still no effort on my amp head. Could it be possible that the pcb board, where the jack is soldered on the front, is damaged?? Quote Link to comment Share on other sites More sharing options...
spaceatl Posted March 16, 2017 Share Posted March 16, 2017 I am less familiar with the head. However, I did the SV Pre mod on my SV 112 that replaced the input board. hmmmm....Here's a thought. Kind of a pain in the a$$, so I am sorry for that...Another approach could be to get a solder sucker and remove the jack from the PCB. That may help you find exactly which pins you need as it can be hard to meter when components are on the board. I think you will need to solder to three pins as you will need to get the tip (+) , ring (-) and sleeve (-). They might have a trace between them already or you could do a jump wire. Quote Link to comment Share on other sites More sharing options...
BillBee Posted March 16, 2017 Share Posted March 16, 2017 I am less familiar with the head. However, I did the SV Pre mod on my SV 112 that replaced the input board. hmmmm....Here's a thought. Kind of a pain in the a$$, so I am sorry for that...Another approach could be to get a solder sucker and remove the jack from the PCB. That may help you find exactly which pins you need as it can be hard to meter when components are on the board. I think you will need to solder to three pins as you will need to get the tip (+) , ring (-) and sleeve (-). They might have a trace between them already or you could do a jump wire. I think your first suggestion is the way to go Space. With the meter set to continuity put a cable in it and see where to tag the leads onto the existing solder points. I am not sure if there is continuity on the "Guitar Sense" that some inputs have. But a->a, b->b and c->c usually works really well. :) Quote Link to comment Share on other sites More sharing options...
manix1979 Posted March 17, 2017 Author Share Posted March 17, 2017 Finally I did it. Line6 you are insane... Right after the guitar jack starts the digital modeling. Why making design like this? Thanks to the service manual with all schematics... Quote Link to comment Share on other sites More sharing options...
manix1979 Posted March 17, 2017 Author Share Posted March 17, 2017 Now an other "problem" starts suddenly appearing. I play with the Helix over the clean channel of the amp. Connecting the guitar direct to the amp... no noise... Connect with the Helix and then to the guitar input. The new made or the original one, brings up a big and disturbing hum. NOW the joke comes... if I play direct in front of the amp with the back turned to the amp... no hum... just turning a bit on the side it hums. I guess it could be the ground... I try the ground shift of the helix next time and tell more then. If the amp is equiped with a ground shift or not I am not sure. Well, isolate the ground wire on the cable does the job as well. AND yes, taking away the ground on the amp is a dangerous, I know ;-) Just for testing. Biasing is a dangerous thing as well ;-) In this case I know what I am doing.. These are just thouhgts from where the hum could come. Tried serveral guitars with and without wireless and of course with diffrent cables. Always the same. Greetings from Austria Quote Link to comment Share on other sites More sharing options...
spaceatl Posted March 17, 2017 Share Posted March 17, 2017 Ok, I have to ask...If you have a Helix, why would you even bother running through the SV modeling?...just curious...If it were me, I would just run helix into the power amp in and be done. That extra wire in there is an antenna that can pickup electromagnetic noise...You could put a lift switch on the negative as you might be getting a loop there. Greetings for USA! What part of Austria? I spent a good bit of time in Vienna and Salzburg back in the 90s... Quote Link to comment Share on other sites More sharing options...
manix1979 Posted March 17, 2017 Author Share Posted March 17, 2017 Ok, I have to ask...If you have a Helix, why would you even bother running through the SV modeling?...just curious...If it were me, I would just run helix into the power amp in and be done. That extra wire in there is an antenna that can pickup electromagnetic noise...You could put a lift switch on the negative as you might be getting a loop there. Greetings for USA! What part of Austria? I spent a good bit of time in Vienna and Salzburg back in the 90s... I am located in Tyrol, Neighbor of Salzburg ;-) I know what you mean.. just let me explain why I use anyway the modeling on the HD100. Running the front input gives me a warmer and brighter tone and of course a fast way to use the EQ. The Helix is good but there is still a diffrence in the sound. EQ can not be easy controlled. Maybe I am using too much of these things and it sould be really the power amp connector. My ears are open for a good solution or maybe just a hint how to get out the best sound what is possible. I agree, the wires inside could catch an extra signal. They are double shielded but who knows. What about using the ground shift buttons on the Helix or the amp? If this does not work, the solution is clear. Deactivate the connector at the back and that sould it be. Strange and still a miracle: Why just with Helix and diffrent guitars that annoying humming?! If the guitars are connected direct to the amp (my newly installed port or the original one) there is silence... pure silence. Just as it should be. Greetings Quote Link to comment Share on other sites More sharing options...
psarkissian Posted March 17, 2017 Share Posted March 17, 2017 Get away from any florescent lights that may be close by. Quote Link to comment Share on other sites More sharing options...
manix1979 Posted March 17, 2017 Author Share Posted March 17, 2017 No lights near the amp or near me while moving around Quote Link to comment Share on other sites More sharing options...
psarkissian Posted March 17, 2017 Share Posted March 17, 2017 Good,... I asked because, electric guitars or tube amps are like noise antennae when it comes to florescent lights. Check that off the list then. Have to remember that with valve (tubes) amps, there's always going to be a little noise. It's just the nature of vacuum tubes. Quote Link to comment Share on other sites More sharing options...
manix1979 Posted March 18, 2017 Author Share Posted March 18, 2017 A litte noise is ok ;-) This is too much... way too much. Quote Link to comment Share on other sites More sharing options...
spaceatl Posted March 19, 2017 Share Posted March 19, 2017 I completely understand where you are coming from on the quick EQ on the HD100 and why you are running through the front. I have worked with the XT, SV, HD models for a very long time. HD was the first generation Line 6 released where I was able to get a satisfactory FRFR tone (direct without a tube amp or tube buffer in the path). I have some experience with the Helix models and to my ears they are higher resolution than the HD models. The models in the SV are basically PRE models and I think that is the real trick to it. That is how I run generally as I often use my HD POD with my SVs and it is PRE models 90% of the time. There are some low gain amps that sound better using the FULL version, but generally I start with the PRE models. I think it's nearly the same with the Helix as HD....It took me a bit to adjust from the XT/SV generation of modeling with HD came out. The resolution is much higher and it is different on a sublime level. Now that I am used to it, I hardly ever use the XT or SV modeling. Always HD....And I am really wanting to move to Helix. When I spoke of a ground LIFT on your new wire, what I mean is that you could install a SPST switch on the negative wire to see if that kills the hum...Is your wire twisted? Shielding does almost nothing inside the chassis as shields only protect from electrostatic noise...You need tight twisted pair with an even number of twists to cancel electromagnetic noise. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.