Adding onboard reverb to a tube amplifier FV1

[waddis]

Hi .... I have just built a Clone of a Vibro champ 5 Watt Tube amplifier...its great. I am looking at making a few for friends and would like to include reverb into it. For my prototype I stripped down a JHS 3 Reverb pedal and wired it directly into the amp only using the Mix and Delay controls and wiring the tone for a mid position. I bought the two control pots to the front panel and are really enjoying the reverb it gives. Its nice having a range from short slap back to ambient. After seeing it uses the FV1 I am now staring down the rabbit hole of FV-1, plenty of really good info around and I've begun my journey. I need to keep anything I build simple as it will just be a small chassis mounted enclosure housing the reverb circuit and doing nothing else but providing some built in reverb for the amp and trying not to look too out of place on a tube amp chassis

Would the onboard reverbs in the FV1 get me the type of reverb I'm after (similar to what I currently have) or will I need to use an EEPROM to find something slightly unique to get what the existing pedal does with the mix and delay pots

I know I will get hit with  'Just build it and see what you think' but any comments appreciated. Just out of curiosity also the example I am using has a 24LC64 EEPROM where as all that I see on the FV1 forums and the spin website are 24LC32 chips, are they compatible?

Thanks

[Digital Larry]

1. Does this one have an EEPROM?  If not, then it's one of the built-in patches.  Never mind DUH you just said it has a 24LC64.  So then, hard to say.

2. If they used a 24LC64 then it might have been due to supply issues on the 24LC32 as the '32 appears in all design documentation.

[waddis]

Thanks for the reply.....I'm not sure what algorithm was used in that pedal, I have heard people say its similar to hall but I have seen a comment from JHS saying it was based on a plate. I have seen Josh of JHS also say that it was a buggy bit of code that he liked. Anyway Im not after building a complex standalone reverb pedal just something to add a bit of depth to a small Tube amp. After trying several cheap reverb pedals that I didn't like the JHS 3 reverb pedal gave a really nice reverb at low volume and if needed could have the mix and delay turned up be to provide some almost ambient texture. Its a small amp and if it can be used standalone with some useful reverb thats what I am after.

The JHS pedal I modded to just 2 knobs by removing the tone knob and fixing its value to mid works well, I'm not sure if I can get the same thing from a BDTR-3H, it looks like it possibly would be simpler. Perhaps the onboard algo's in the FV1 can be made to sound like the JHS pedal or someone else's reverb code would be close. It would be great to not go down the programming rabbit hole if I can avoid it...I'm already spending too much time in there doing the tube amp thing!

Anyone who has used or seen the JHS 3 reverb pedal and can comment on what I can do to achieve something very similar would be appreciated

Thank

[Ice-9]

You can use the Fv-1 Reverb programs if you want to but it is worth adding an EEPROM in case you wanted to add an external program.

I used to have the (Van Halen) EVH 5150 Mk3 combo amp and the reverb inside the amp was just the FV-1 internal reverb and it sounded great.

[DIY Bass]

In order to program an EEPROM you would need a programmer.  If you have a programmer you may well be able to read the JHS EEPROM code.  Having said that for what you are looking at I think I would be very tempted to just use the internal programs

[waddis]

Thanks...I did find a couple of pedals that just use the internal reverb programs and they sounded OK, one was the BYOC l'l reverb and as you mentioned plenty probably just use the onboard reverb in integrated amp builds. I want to custom build a PCB to fit into a small aluminium enclosure that will not look out of place on the tube amp chassis. I'm looking at a chassis mounted connector so the module can be plugged in to take the power, in/outs and pots with a true bypass toggle switch on it to restore the amp back to reverbless if someone desired.

So I guess if I'm going to make a PCB I may as well put the EEPROM socket in as an option. The more I read up I think I'm getting an understanding of the FV1. Next challenge is designing the PCB and getting a few made, last time I made a PCH was 30 years ago with some tape and dots! any suggestions on a good designer program or are there places that will take a schematic and make a few boards? any suggestions?

[waddis]

Also...would one of the cheap chinese based EEPROM programmers eg: EZP2023 work for what I may want to do just to get some of the code available at spin or mstratman onto the EEPROM? I've still got a bit of research to do to get my head around this process but what I understand hopefully is that the code available can be burnt onto the EEPROM via the cheap programmer using its supplied operating software? then that EEPROM placed in its socket on my PCB and if pin selected on the FV1 it will use that code.

I understand I could go down the developer board path if I wanted to tweak the code or do lots of experimentation but for what I want at this stage to just get something basic up and running

If I did want to get into code tweaking could I still use the spin asm language etc from one of the spin community code writing tools and then burn that code from that program to the EEPROM via the cheap programmer? I guess the downside of this is having to constantly shift the EEPROM around to try it out which I guess is the idea of a development board?

Appreciate any feedback or comments and sorry for the noob questions

[ElectricDruid]

I'm looking at a chassis mounted connector so the module can be plugged in to take the power, in/outs and pots with a true bypass toggle switch on it to restore the amp back to reverbless if someone desired.

If the internal programs are wet-only with the dry signal mixed on the analog side, you wouldn't need the true bypass - just turning the reverb control down to zero would do it.
I couldn't find a definitive answer about whether the internal programs are mixed or wet-only though. There's a suggestion on this page that they might be, but it doesn't say which programs are and aren't:

http://spinsemi.com/programs.php

Perhaps someone here knows?

[waddis]

The bypass switch would really only be there in case the Reverb module failed or was playing up for some reason, as you mentioned turning the mix down should effectively just let the input signal through. I was keen on having the Reverb module able to be removed and a bridging connector plugged into its place to hardwire bypass the unit if the unit did fail or someone in 50 years time couldn't get one! This whole tube amplifier thing I'm enjoying at the moment has made me realize that the simplicity of the amplifier circuit, hand wired point to point and its discrete nature with no software has a certain appeal.

[waddis]

Also...would one of the cheap chinese based EEPROM programmers eg: EZP2023 work for what I may want to do just to get some of the code available at spin or mstratman onto the EEPROM? I've still got a bit of research to do to get my head around this process but what I understand hopefully is that the code available can be burnt onto the EEPROM via the cheap programmer using its supplied operating software? then that EEPROM placed in its socket on my PCB and if pin selected on the FV1 it will use that code.

I understand I could go down the developer board path if I wanted to tweak the code or do lots of experimentation but for what I want at this stage to just get something basic up and running

If I did want to get into code tweaking could I still use the spin asm language etc from one of the spin community code writing tools and then burn that code from that program to the EEPROM via the cheap programmer? I guess the downside of this is having to constantly shift the EEPROM around to try it out which I guess is the idea of a development board?

Appreciate any feedback or comments and sorry for the noob questions

[bluebunny]

I couldn't find a definitive answer about whether the internal programs are mixed or wet-only though.  . . .  Perhaps someone here knows?

Call for Digital Larry!

[dschwartz]

I couldn't find a definitive answer about whether the internal programs are mixed or wet-only though.  . . .  Perhaps someone here knows?

Call for Digital Larry!

The reverbs are wet only and the parameters are length, lopass and hipass. The mix can be controlled externally. You can add a switch to have different lengths and hi-lo pass.

[ElectricDruid]

The reverbs are wet only and the parameters are length, lopass and hipass. The mix can be controlled externally. You can add a switch to have different lengths and hi-lo pass.

Excellent! There you go! You can build an FV1-in-a-can and wire it up just like a reverb spring! Turn up reverb knob for reverb, turn down for the same signal you had before with no digital mucking about. Dead simple.

[waddis]

Thanks ......just looking into making custom PCB's using easyEDA, will add the EEPROM just in case.

Might even put a leather cover over the small chassis mounted FV1 unit just like the real reverb tank! Next build will be a Princeton Reverb so no software involved with that, got a real spring tank set to go.

Still would be good to get some comment on using the EEPROM programmer and not needing a developer board as per previous post. If just using a programmer like the EZP2023 to add code from whats publicly available to try out some different reverbs is practical then I'll go ahead and order one. Thanks again

[Digital Larry]

I have used a PICKit 2 clone to program on I2C in circuit.  I also hear CH341 works but gave mine away before trying it.

DL

[waddis]

Just ordered a CH341a which hopefully will be OK, the only thing I could seem to find was to make sure it could be set to 3.3 volts

[mark2]

I use a super cheap CH341A USB programmer and it works fine. You may need to download drivers for your computer, but otherwise no issues.

I don't think it needs to be set to 3.3V. The 24LC32 works fine at 5V too.

[waddis]

Thanks Mark..Im an OSX user and there looks like enough software out there to read and right from that platform, all still new to me, need some hands on time with it.

[puretube]

Anybody knows where to find Test- or Programming- Sockets for 8-pin SMD EPROMs?
(I`m asking for a friend ...)

[ElectricDruid]

Anybody knows where to find Test- or Programming- Sockets for 8-pin SMD EPROMs?
(I`m asking for a friend ...)

eBay is my usual source for stuff like that. You might find programming sockets at the big component suppliers, but manufacturers like to charge stupid prices for anything that qualifies as "development tools", so they can get stuffed.