Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: jackplug1 on May 06, 2023, 10:47:09 am

Title: Adding FX loop to seplex build for a stand alone reverb
Post by: jackplug1 on May 06, 2023, 10:47:09 am

Would the best place to position it be between the tone stack and V2B, where the boost switch is placed (which I have not included)
Could this not a good idea if distortion occurs after the FX loop.

Title: Re: Adding FX loop to seplex build for a stand alone reverb
Post by: sluckey on May 06, 2023, 10:53:46 am

All the stand alone reverb units I've seen are meant to be inserted between the guitar and amp. This makes them usable for any amp.

Title: Re: Adding FX loop to seplex build for a stand alone reverb
Post by: AmberB on May 06, 2023, 03:23:04 pm

Just a suggestion, an easier place to attach the center tap of the heater winding would be to the cathode of the power tube.  That will raise the heater reference by whatever the cathode voltage is and save you a few parts in the power supply, and the space that those parts would require.

Title: Re: Adding FX loop to seplex build for a stand alone reverb
Post by: jackplug1 on May 07, 2023, 05:09:12 am

Quote from: sluckey on May 06, 2023, 10:53:46 am

All the stand alone reverb units I've seen are meant to be inserted between the guitar and amp. This makes them usable for any amp.

The distortion generated by the amplifier pre-amp stage would make the reverb sound bad so that is the reason I would like to have it inserted into an FX loop.

Title: Re: Adding FX loop to seplex build for a stand alone reverb
Post by: pdf64 on May 07, 2023, 12:20:35 pm

For a master volume amp, fx loops are usually inserted immediately before or after the master volume control.
I think your signal level there will be too high though, nevermind the confusion it’d cause the nfb.

Title: Re: Adding FX loop to seplex build for a stand alone reverb
Post by: tubenit on May 07, 2023, 12:44:42 pm

I added an FX loop to a SE amp like this.  It worked with 3 different delays and a reverb pedal and sounded fine to me.  The guy I made it for likes it real well.

Here is a soundclip of the amp. https://soundclick.com/share.cfm?id=13752309

With respect, Tubenit

Title: Re: Adding FX loop to seplex build for a stand alone reverb
Post by: Lectroid on May 07, 2023, 01:32:40 pm

Every time I listen to that amp, I'm blown away.  If I ever build anything that sounds half as good as the CSB, I'll die happy.   :icon_biggrin:

Title: Re: Adding FX loop to seplex build for a stand alone reverb
Post by: jackplug1 on May 08, 2023, 11:42:58 am

Quote from: tubenit on May 07, 2023, 12:44:42 pm

I added an FX loop to a SE amp like this.  It worked with 3 different delays and a reverb pedal and sounded fine to me.  The guy I made it for likes it real well.

Here is a soundclip of the amp. https://soundclick.com/share.cfm?id=13752309

With respect, Tubenit

Thank you for sharing that, the music is good and that amp sounds great.
You have confirmed what I was thinking about the placement of the FX loop
Are the extra pots on the send and return necessary as the outboard FX should have a gain control?
Does the larger 5uf on the cathode of v1 make a difference ? more fender, less marshall?