Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: joesatch on August 19, 2022, 01:33:56 pm

Title: 3 button footswitch with a TRS ?
Post by: joesatch on August 19, 2022, 01:33:56 pm: Is this possible? I have 3 relays in the amp each activates with a ground. Theoretically a TRS can have 3 combinations. How?

Tip-Ring
Tip-Sleeve
Ring-Sleeve
Title: Re: 3 button footswitch with a TRS ?
Post by: sluckey on August 19, 2022, 02:01:46 pm: not possible
Title: Re: 3 button footswitch with a TRS ?
Post by: SILVERGUN on August 19, 2022, 02:55:38 pm: Have you seen TRRS?
I have only seen them in 1/8", but that should do it.
Title: Re: 3 button footswitch with a TRS ?
Post by: PRR on August 19, 2022, 04:34:13 pm: Tip-Ring
Tip-Sleeve
Ring-Sleeve

If you connect T and R, and T and S, then you already have an R and S connection.

So there's no 3rd state.
Title: Re: 3 button footswitch with a TRS ?
Post by: tubeswell on August 19, 2022, 05:07:12 pm: TRRS Plug
https://www.aliexpress.com/item/1005001844728786.html?spm=a2g0o.ppclist.product.2.ee01Ej8dEj8dZm&pdp_npi=2%40dis%21NZD%21NZ%24%2016.20%21NZ%24%2016.47%21%21%21%21%21%400b89a67f16609467001325759e79b9%2112000017826237508%21btf&_t=pvid:67747b44-8aa3-41f0-a09a-5c8ece20571c&afTraceInfo=1005001844728786__pc__pcBridgePPC__xxxxxx__1660946700 (https://www.aliexpress.com/item/1005001844728786.html?spm=a2g0o.ppclist.product.2.ee01Ej8dEj8dZm&pdp_npi=2%40dis%21NZD%21NZ%24%2016.20%21NZ%24%2016.47%21%21%21%21%21%400b89a67f16609467001325759e79b9%2112000017826237508%21btf&_t=pvid:67747b44-8aa3-41f0-a09a-5c8ece20571c&afTraceInfo=1005001844728786__pc__pcBridgePPC__xxxxxx__1660946700)

TRRS Socket
https://www.aliexpress.com/item/1005003625556809.html?spm=a2g0o.productlist.0.0.184d2034nskP77&algo_pvid=4f1b1bc6-cc03-436b-bc97-7dd2939dcc37&aem_p4p_detail=202208191506256098821295850002958776&algo_exp_id=4f1b1bc6-cc03-436b-bc97-7dd2939dcc37-0&pdp_ext_f=%7B%22sku_id%22%3A%2212000026550578837%22%7D&pdp_npi=2%40dis%21NZD%214.65%213.63%21%21%21%21%21%402103399116609467850716228eb610%2112000026550578837%21sea&curPageLogUid=CXPbgD1nc99y&ad_pvid=202208191506256098821295850002958776_1 (https://www.aliexpress.com/item/1005003625556809.html?spm=a2g0o.productlist.0.0.184d2034nskP77&algo_pvid=4f1b1bc6-cc03-436b-bc97-7dd2939dcc37&aem_p4p_detail=202208191506256098821295850002958776&algo_exp_id=4f1b1bc6-cc03-436b-bc97-7dd2939dcc37-0&pdp_ext_f=%7B%22sku_id%22%3A%2212000026550578837%22%7D&pdp_npi=2%40dis%21NZD%214.65%213.63%21%21%21%21%21%402103399116609467850716228eb610%2112000026550578837%21sea&curPageLogUid=CXPbgD1nc99y&ad_pvid=202208191506256098821295850002958776_1)

The tiny size of the plug will limit cable thickness/resilience , so probably impractical for a geetar amp setup
Title: Re: 3 button footswitch with a TRS ?
Post by: thetragichero on August 19, 2022, 05:20:38 pm: so it is *possible* (check out the fender m-80 chorus or fender Princeton chorus) but requires a bunch of additional circuitry
for diy a 5-pin din connector is your friend
Title: Re: 3 button footswitch with a TRS ?
Post by: nandrewjackson on August 19, 2022, 05:52:31 pm: The fender red knob twin uses a T/S for 2 switching operations. It feeds an AC signal and each footswitch has a series diode, so only either the positive side or the negative side is activated.
Your solution may be in that logic somehow.

I can't remember the internal switching circuit, but I know that's how the footswitch works on that one.

That schematic may also be difficult to find a nice clear legible version.
Title: Re: 3 button footswitch with a TRS ?
Post by: nandrewjackson on August 19, 2022, 05:57:38 pm: +1 for a DIN (midi) cable for footswitch. The sockets and cable are just as easy to purchase as 1/4" equipment
Title: Re: 3 button footswitch with a TRS ?
Post by: joesatch on August 19, 2022, 10:36:55 pm: is possible with some extra parts inside the amp. i will figure this out.
Title: Re: 3 button footswitch with a TRS ?
Post by: acheld on August 20, 2022, 10:21:00 am: I've had good luck with DIN connectors and multi conductor cables designed for this. I like relays, though they certainly do increase the complexity of a build.

Take care that your connectors -- panel and cable -- are in fact compatible.

Newark has a great selection, PartsExpress as well.
Title: Re: 3 button footswitch with a TRS ?
Post by: Williamblake on August 20, 2022, 05:16:40 pm: Why not use some diodes for making four circuits out of two?