Adding an FX loop to a Fender Rivera Super Champ and Champ II

[ES225]

I asked this question about a year ago but then got sidetracked with other things. I did some mods to these maps and now they sound very good. However, they are desperately in need of an FX loop.
If the gain is increase any amount they start hating delays and reverbs up front. It sounds awful, as you know. I have to turn these effects way down to even make it acceptable.
My question:
What would be the cheapest and best way to add an FX loop to these maps. I heard that its actually difficult to add an FX loop to amps and also get them to sound good.
Somoene suggested that Mojotone has a DIY board that can be installed. I don't know how well this works and if its my best option.
I know that I could remove the Reverb in and out jacks and put in in a send and receive in their place. I am not using the reverb anyway and removed the tank.
So my question is, can this be done and will it work once done, or will it suck the tone from the amp and make me regret doing it. Will there be any difficulties in installing an FX loop. Would a pre-made circuit, like the Mojo be perfect?
These amps can be like mini Boogies if they only had an FX loop.

[Chuck H]

Adding an effects loop that does more good than harm integral to any amp is complicated by circuits specific to each amp considered. The Rivera amp would not do well with the reverb send used as an effects send. The pre fabricated Mojo kit is not a cure all for every application and (IMO) doesn't really apply to your amps. A simpler solution...

Add a simple line out to each of your amps that you want to run effects with. Then you can use the signal from the line out to feed effects and re amplify them with a completely different amp analagous to the one you're playing. You seem to have several amps so this would seem possible.

EDIT: The "line out" I'm referring to consists of a resistor and a 500 ohm pot connected to the amplifiers output jack. The resistor value is determined by the specific amplifier. The line out can serve as a direct feed for low and line level signal to any peripheral devices like mixers or effects and, subsequently a slave amp.

I had a similar problem to yours with one of my own designs that is intended to be run cranked up for power tube distortion. One of my customers wanted to add reverb. Rather than trying to implement an on board reverb I built him a dedicated "reverb amp" combo that filched power from the host amp to drive a reverb tank and then amplify the reverb only signal through the "reverb amp"s speakers. It sounds great and there's no garble from distorting power tubes or less than ideal signal levels. The solution I'm proposing for you is the same concept.

[glebert]

A simpler solution...

Add a simple line out to each of your amps that you want to run effects with. Then you can use the signal from the line out to feed effects and re amplify them with a completely different amp analagous to the one you're playing. You seem to have several amps so this would seem possible.

I've done this off the speaker outs on amps. I put a voltage divider in between the speaker out and the effects pedals to scale the effects input level, then reamping with a small, clean amp. Sounds fantastic.

[ES225]

I do want to contain everything within one amp and keep things simple. I thought adding an FX loop would not be complicated. I guess it is. I wonder if that Mojo board will do the trick and I can simply mount it in place of the reverb jacks in the back of the amp and it would not detract from the look of the amp.