The Electric Piano Forum

Repairs, Maintenance & Upgrades => Preamps, Modifications & Upgrades => Topic started by: leanbow on November 30, 2016, 11:18:52 PM

Title: Warneck 200A replacement amp Install details/resources?
Post by: leanbow on November 30, 2016, 11:18:52 PM
I am installing a Warneck 200A replacement amp and I am looking for install resources  (images, videos etc)

The written instructions are leaving some questions for me and I am trying to replace some of my pianos wiring with shielded and new 1/4" jacks.  Also, some of my cabling looks modified/hacked so it is hard to match to what "should" be there or is expected to be there.

I apologize in advance if I am missing an obvious source online but I would appreciate a nudge in the right direction.
Title: Re: Warneck 200A replacement amp Install details/resources?
Post by: cinnanon on December 01, 2016, 03:34:21 AM
Take some pictures for us some we can see if your wiring is original. Verify the original wiring matches the original schematic first, then it should be an easy drop in replacement.
Title: Re: Warneck 200A replacement amp Install details/resources?
Post by: retro-mike on December 02, 2016, 02:41:41 PM
Hi
Here is a layout diagram :)
http://www.retrolinear.com/media/20650/200a_LAYOUT.pdf

We are working on install videos, its been on the TO-DO list for a while!!


if you have any other questions or need help please don't hesitate to contact us, were here to help ;)
215-699-8000 or you can email info@retrolinear.com


Thanks
Title: Re: Warneck 200A replacement amp Install details/resources?
Post by: leanbow on December 04, 2016, 03:11:25 PM
Thanks for looking.  The issue lies in the speaker, aux out and Phone jack.  The phone jack cable was just cut and lying in the case when I opened it and the aux out was loose and hanging in there too.  The speakers just cracked and popped but I was able to hear sound from the keys between cracking and popping.

The new board is in and I would like to finish the two jacks and the speakers (hoping to install new 1/4 jacks in to the 'aux' and 'phones' too)

I noticed the original 'aux' jack has two resistors - (one mounted to the amp board and one on the jack) which I am not sure if they are still needed or compatible with the Warneck amp.

Your original response was to clear up the stock wiring first but it was already taken out by me and the amp was half in.  I followed instructions and feel like most of it is squared away except the speakers, aux and Phone jack.  I attached some overhead shots of the install to get a double check if you had time to look at those. Super appreciated. The fuse is not in yet or the resistor on the vibrato for lack of time to pick up parts.

Title: Re: Warneck 200A replacement amp Install details/resources?
Post by: leanbow on December 04, 2016, 03:19:44 PM
Thank You Retrolinear.  That image was a big help for the pots.  Your images suggestion to run the grounds under the board was smart...Thanks again.

The Aux out made sense after looking at some pictures online, the wurlitzer schematic and figuring out I had confused the two jacks and thought they tied together somehow (mistake on my part)

I could really just use detail from the speaker out jack on the amp board to the speakers and to the headphone jack it would be appreciated. Resistor values and where they should run would help too.
Title: Re: Warneck 200A replacement amp Install details/resources?
Post by: leanbow on December 06, 2016, 02:33:03 AM
So bumped in to this and have an answer for my previous post.  Solution for speaker wiring and jack is to use the right replacement jack - a switch jack. (not the one I pictured above and planned to use) Part numer is Switchcraft 12A (switchable version of the standard Switchcraft Mono Jack). The enclosed version which looks most like the original is Switchcraft 112AX. I found the best description of how to wire it in an article written for re-wiring toys strangely.

The article has installation notes too. http://performermag.com/best-instruments/circuit-bending-for-beginners/

thanks for the help and documents for install.


Title: Re: Warneck 200A replacement amp Install details/resources?
Post by: cinnanon on December 06, 2016, 10:08:29 AM
The aux out jack you want (that also matches the schematic) is a switchcraft 11.  The one you want for the Headphone jack is the switchcraft 13A (also matches the schematic). I wouldn't fart around with wiring a stereo headphone jack (if you were thinking of doing so) because if someone plugs a mono jack in there it will short out the amp.
Title: Re: Warneck 200A replacement amp Install details/resources?
Post by: pianotuner steveo on December 06, 2016, 03:59:55 PM
How would it short out the amp? It's a mono amp anyway...You are just sending a mono signal to both sides of the headphones when you use a stereo Jack.
Title: Re: Warneck 200A replacement amp Install details/resources?
Post by: cinnanon on December 06, 2016, 04:48:13 PM
Quote from: pianotuner steveo on December 06, 2016, 03:59:55 PM
How would it short out the amp? It's a mono amp anyway...You are just sending a mono signal to both sides of the headphones when you use a stereo Jack.

My thinking is that if you send a signal to the Tip and Ring of a stereo jack, and you plug in a Mono plug, the Ring of the jack (R or L) will be sent to Sleeve of the Plug (Ground)...
Title: Re: Warneck 200A replacement amp Install details/resources?
Post by: pnoboy on December 10, 2016, 04:48:41 PM
Quote from: cinnanon on December 06, 2016, 04:48:13 PM
Quote from: pianotuner steveo on December 06, 2016, 03:59:55 PM
How would it short out the amp? It's a mono amp anyway...You are just sending a mono signal to both sides of the headphones when you use a stereo Jack.

My thinking is that if you send a signal to the Tip and Ring of a stereo jack, and you plug in a Mono plug, the Ring of the jack (R or L) will be sent to Sleeve of the Plug (Ground)...

Correct
Title: Re: Warneck 200A replacement amp Install details/resources?
Post by: pianotuner steveo on February 10, 2017, 07:09:08 AM
I didn't think of that...
If it can short out, I would label the jack with a warning not to plug in a guitar type cable or mono headphones. I would personally rather have a stereo Jack wired for mono so audio will be in both sides when using stereo phones.
Title: Re: Warneck 200A replacement amp Install details/resources?
Post by: cinnanon on February 10, 2017, 11:48:54 AM
Quote from: pianotuner steveo on February 10, 2017, 07:09:08 AM
I didn't think of that...
If it can short out, I would label the jack with a warning not to plug in a guitar type cable or mono headphones. I would personally rather have a stereo Jack wired for mono so audio will be in both sides when using stereo phones.

I personally would rather have the stock mono headphone jack to prevent shorting altogether (or remove it like Max did!)  I'd build a small mono-to-stereo headphone adapter for external use if I was that concerned. Then again, how many of us are still using the headphone jack for headphones? If static hits or a reed breaks, isn't it super loud??