Concert II Discussion

[proaudioguy]

Wow the fx loop thing really opens the lead channel. Amazing what a difference it makes. I've pretty much made my mind up. I'm going to rebuild the lead and clean channels. I am just debating on whether to use the existing eyelet board or start from scratch. Going to try to work out a new layout and see where that goes. I'm kind of lost in that area. I want it to be extremely neat and tidy and have the audio runs as short as possible and the grounds on a bus, Hoffman style. Probably easier to start from scratch than rework the board.

Need lots of help with component choice. For clean a good 3 dimensional black face Deluxe reverb is where it's at for me. For lead anything from a cranked deluxe reverb to a cranked 59 bassman to the RF dumble tones. I would very much like to be able to clean up with the volume on the guitar. I would like the individual notes to be heard in a chord. I would like to avoid intermod distortion.

[vibratoking]

I thought you might like the effects loop trick.

That amp has a little collectability...sad to see it get modded. Perhaps I can talk you into saving it? I sold mine recently for $750. That would be a good start at what you really want and you could save another Fender.

My $0.02

[proaudioguy]

That amp has a little collectability...sad to see it get modded.

My $0.02

I disagree but time will tell. I just missed one that sold for $375 and it was a 2x10" model. There are thousands of these amps out there. It's possible it (this model) will increase in value but I'm not a collector.

Why did you sell it?

I wanted a fender clean and a Dumble OD with an fx loop and fender reverb which is why I bought this instead of an ODS kit.

[vibratoking]

Why did you sell it?

Two reasons:

A good friend fell in love with it.

I already own upwards of 20 amps and it is well past time for a reduction.

[Mark]

My thoughts on the Concert II conversion are firstly mod the Fender gain channel with as few changes as possible to a Dumble channel (with OD engaged.)

My reason for this is you may not like what you hear, I would experiment with the various Dumble pre-amp topologies till you find the one you like.

The other reason for my opinion is I have been working with converting a D'Lite to a #0102 amp, I've heard the D'Lite amp sounds better with a larger Bassman style output transformer. I decided to mod my Boogie SOB to a #0102 amp to hear the difference between output transformers.

To my utter surprise the D'Lite 22/33 watt transformer sounds better than the Bassman style transformer in my Boogie. I did try going from the D'Lite pre-amp to the Boogie P.I. & pwr amp and the difference in sound is the coming from the output stage.

The question I now ask myself is; what is a good output transformer for these amps?

[proaudioguy]

I'm going to pull the V1 Snubber then listen to the clean. I'm going to change the clean to a straight up DR which is extremely easy to do because I think I have to remove the resister on the Vol pot and change the Bright switch circuit and that's it.

Changing the lead into a dumble on OD requires adding the V4B tube and a trim pot (at least temporarily). I am not too sure where to put the components for V4B. It's not a small mod. Also the wire in all of these Rivera era amps has insulation that melts extremely easily. Not an issue when assembling because they dip the tip of the wire in a solder pot to tin it and pre flow the eyelets then just dunk the wire in. De-soldering requires enough contact to melt the insulation and in a few cases I've had it look pretty ugly. The wire I normally use doesn't have this problem. I replaced the heater wires in my Superchamp as well as a few other things for clean up purposes and the amp is very quiet now. The practice of keeping all the pin 9s together and all the pins 4/5 together was not used with these amps either. I have been told this is very important although I don't know if that's true or why it would be important.

In regards to owning 20 amps, wow, they make a TV show called Hoarders that you should be on . Seriously I have 3 amps in my possession (my 93-95 concert will be gone Monday so that doesn't count), 3 guitars, and only 2 hands. I inherited the third guitar which I rarely pull out, but I can't sell because it's a family thing. I bought my second guitar because I was constantly moving between standard, 1 step down, and half a step down. I prefer 1 step down, but keep one at standard because it's too hard to jam with friends spontaneously. I could really get on fine with 1 guitar and was for many years. Never even broke a string, but I play with 11s now so I doubt I ever will. I have a Twin Reverb I restored because it was in shambles when I got it. It's not exactly original, but looks like it. It has a Turret board, and a bias vary trem. Sounds sweet. Can't sell it, but can't really lift it either. It's a Twin and it's loaded with EVs. It sits under my piano and I play it when wifey is gone. I debated modding it to use one of the channels as the dumble style gain, but I really like it as is. I also have a Superchamp because I like them and when I found one back in the early 90s and had to have it and it's a good thing cause I never saw another one until ebay. I have the Concert Amp which was a gift someone gave me when they saw me looking at a rivera concert (for $350) back in the mid 90s. I had done a solid and this was their way of showing appreciation. I didn't buy that other amp because it would have been a slap in the face (it was on consignment in my friend's store). It's sold with 2 days left for the bidding war. Not sure of the terms around here so I won't put the link here. It's a fantastic amp but I needed to fund the latest, which is the subject of this thread. Now with all these toys I consider myself a bit of a hoarder unless I can justify the purpose of all of of them!

[lovetone]

I have found that the clean tone stack is a little mid scooped. I find that if you remove the 0.047uf from the end of the bass pot and put say a 24k resistor from the free end to earth it sounds much more open with more general brightness. I also change the slop resistor to 150K.

Hope that helps

Geoff

[proaudioguy]

I have found that the clean tone stack is a little mid scooped. I find that if you remove the 0.047uf from the end of the bass pot and put say a 24k resistor from the free end to earth it sounds much more open with more general brightness. I also change the slop resistor to 150K.

Hope that helps

Geoff

It's true the blackface fender tone stack only comes close to flat when the treble and bass are all the way down and the mid is all the way up. That only works on the amps that have treble mid and bass. The amps that have treble and bass have the mid control fixed at the middle of where the mid pot would have been.

[proaudioguy]

This amp matches the schematic that shows no 10pF in parallel with the 3.3meg resister between the reverb send and return. How does that affect the amp?

[proaudioguy]

Here is a schematic of my amp with the mods I've made to the clean channel. I'd like to add V4b into the mix.

[proaudioguy]

How does this look?

[Mark]

I can't read a .sch file. Sorry.

[LeftyStrat]

I can't read a .sch file. Sorry.

You can download the free program JSchem here:

http://dhost.info/jschem/

It can read and edit these files, and it runs on Windows, Mac OS X, and Linux.

[proaudioguy]

pdf

[groovtubin]

pdf

just move the OD tone stack after the sec stage, and you`l have a smokin amp man!~ Couple off the paralleled tube to the first OD stage with a .0047 into a 250KA

jp@Omegaamps