Before & After - 6505+ 112 Amplifier Modifications 

The Sheffield is not a bad speaker at all! It records/sounds well in many scenarios if you're not concerned about retaining low end. This speaker gets its fair share of hate but I don't think it's warranted. I do miss the Sheffield + green channel crunch tone.

I preferred the Sheffield speaker on its own, but the V30 probably sits better in thr mix.

Thank you! Every tone has a job! Definitely miss the pre-mods crunch tone some days.

I'm happy to share the schematics denoting the changes I made. Shoot me an email or fill out the "contact us" page at substationonyx.com

You can contact me via the Contact page on my website, substationonyx.com. There might be an email in my YT profile as well. That song is slated for a Dec 2023/Jan 2024 release, and I'd be happy to send you the tabs.

Thank you! I really don't mind the Sheffield at all. I think it's a decent speaker but this isn't the amp for it. It's usable with the 6505, but the V30 just sounds better to my ears.

Could you send me the mods please? A sent an email via your website, but I didn't get a reply yet.

Thanks! I don't have the time/energy to do videos all the time, but I did keep all the schematics that specifically list the part values I exchanged.

@@aric_unhinged Thank you for the reply. If you could share the schematics when you find time, I would be so grateful. My email is the name of my channel and gmail at the end. Thanks a lost in advance!

Thanks, but there is no audio in this video where you're hearing the mods with the original speaker. The original speaker samples are with the amp, stock.

@@aric_unhinged well whatever u did made them sound rather good compared to what i remember.

Good luck! I found modding this amp to be pretty rewarding. Already done a little recording with it since and it's been great.

The Vintage 30 is definitely "ground zero"... there's probably other things your ear would enjoy more, but you can't go wrong with a V30. I'm personally partial to Creambacks. Regarding the music, yeah, I always play my own stuff. You can look up "Aric Fowler" on Spotify, iTunes, etc. and find me. The song you hear in this demo is called 'Crash'.

@@aric_unhinged never tried i creamback. What about eminence guvernor, swap thang etc etc? They have many different ones. Reignmaker too was recommended. Ill check out your music dude :)

The FX loop mod is fairly simple. Tell your tech to solder a 0.022µF ceramic capacitor in parallel with R86 on the 6505+112 schematic, which is easy enough to find online. Make sure it's the 6505+112 schematic, and not the schematic for a 6505+ or 6505, as the components are numbered differently in these documents. R86 is located on the breakoff PCB near the FX loop, and it has a value of 100 kΩ.

On that 22uf cap which one 200v 400v there is a few which one did you use

I didn't mod it to sound like another amp in particular, but the Rhythm channel mods pushed it in a Marshall-y direction. The new Rhythm tone stack is identical to the JTM45/Bassman 5F6 tone stack. I agree that in the end, the Rhythm channel with "Crunch" engaged evokes some kind of British high-gain flavor.

@@aric_unhinged Thanks. I have had this amp for 10 years now but have been wanting a JCM 800 or Plexi sound. Aside from spending thousands of dollars on a JCM 800 or Plexi, I have been wondering if the 6505+ can be made to sound like them.

Sure! Go to substationonyx.com/2023/10/02/modifying-my-peavey-6505112/

Took apart the amp and did it all by hand with a soldering iron. The schematic for the 6505+112 is a short Google search away, and I had most of the electrical components already lying around.

Show him this: substationonyx.com/2023/10/02/modifying-my-peavey-6505112/

Thanks bro

In this case, that would be an incorrectly-applied generalization, but I'm not entirely sure which of the mods you're referring to. EQs in any format can be pretty powerful tools, but they'll only take you so far. An EQ in the (modded) loop of this amplifier may have been able to get close to the revoiced tone stack of the rhythm channel, but it definitely would not have been able to pull off any of the gain-related modifications of the rhythm preamp channel, such as the increased bass response and revoiced gain characteristic, since those two things came from tinkering with the gain structure. Hopefully this helps!

@@aric_unhinged yes, I was just referencing the switch between speakers, not the mods. Well done on the mods!

@@rickhammel9541 Ah! I see. Well this is a spectcular point, glad you brought it up. If you are aiming to match the profile of a speaker to the other one, then I would say that an EQ pedal (e.g. MXR 10-band, Empress ParaEQ, etc.) will not be able to get you to the point where it's believably a different speaker when listening in isolation. A software-based EQ, such as the Pro-Q tool from FabFilter, could potentially get you reasonably close thanks to its matching feature. The curve needed to do it will look very strange and will require more bands with more hyper-specific shapes than any EQ pedal has available. Even this solution will still fail in some areas though, since some speakers don't produce (as an example) super low or super high frequencies, and even very powerful EQs and their multiplicative nature can't compensate for that that (anything x 0 is still 0) if you're trying to replicate a speaker that does produce such frequencies. TL;DR: Cab+speaker systems frequency responses are wildly nuanced and specific, and most EQs paint too broad of strokes to match between them, so it doesn't work too well.