Need suggestions for an amp and cab

[imaradiostar]

I did some amp work for a friend's dad many years ago before I really should have been doing work for money. The amp worked ok but it was never quite right and I'm planning to build something for him to make it right and I'm hoping to have it done before Christmas so that my friend can take it with him and have something for his dad.

I'm really stuck as to what to build him. I made a really nice matching finger jointed head and 4x10 cab. I have the alnico 10" speakers my friend's dad bought many years ago that will go into the cab. I'm planning to use a Fender 40 watt PT and an output from a Baldwin organ- substantial size, 6k6 to 4 and 8 ohm outputs. I also have a Fender twin output TF which could be used but could only be used as 4k to 8 ohms. This amp will really only be used in a studio setting as my friend's dad records music libraries for a living.

My mind is reeling will all the options out there...too many! His dad isn't picky, he doesn't really mind what it is as long as it makes sound though it'd be nice to have clean/dirty options. I'd like for this to be something he can be proud of though.

I was going to build something with a "marshall" high gain channel and a "blackface" channel then it started growing verb and an effects loop and all kinds of stuff that he really won't use and will just make it more difficult to finish in a timely fashion.

I then started leaning toward a simpler Dumble or Trainwreck type circuit...but it seems like they usually end up needing a lot of tweaking and troubleshooting to make them just right. I don't really need that as I'm gearing up for my own trip home for the holidays.

So...do I build something simple (bassman or plexi) and let it be or should I try something like a Trainwreck or Komet circuit?

please help! Need to build very soon!

jamie

[imaradiostar]

wow...my title should have been more specific like "name your favorite 30-50 watt amp".

I'm going to try to change it.

jamie

[imaradiostar]

...and I can't change it. dangit.

sorry for the spam. I feel like such a noob.

jamie

[Tubenit]

For your consideration

I'll offer some considerations for you. I've built both of these amps and enjoy them alot. I don't care if you build them ......... just offering ideas off the beaten path.

Carolina Blues Rocket: Cathode biased 5881 tubes with some switches for gain stage, PAB, NFB & local feedback.
About 25 watts of loud. Great clean and very smooth overdrive.

http://s28.photobucket.com/albums/c2...luesRocket.gif

http://s28.photobucket.com/albums/c2...sRocketcab.jpg

Editable schematic and layout here (you'll need to download ExpressSCH which is free to view them) :

http://www.el34world.com/Forum/index.php?topic=3947.0

Plexi 25w reverb: Cathode biased 5881 with Marshall style topology and paralleled V1 with bright, full, fat switch and NFB switch. Has decent "crunch". Here is a sound bit of the amp played very clean. It does have decent overdrive also.

http://www.soundclick.com/player/sin...&q=hi&newref=1

http://s28.photobucket.com/albums/c2...lexi25RMTS.gif

Editable schematic and layout:

http://www.el34world.com/Forum/index.php?topic=567.0

With respect, Tubenit

[imaradiostar]

Thanks for replying to another one of my crazy ideas. I started to build an amp based on one of your other designs but I found myself in bed with a cold for most of the weekend...so that'll have to wait!

I'm really interested in both of these ideas. I'm assuming the more "marshall" of the designs crunches a little better while the Carolina amp probably is more of a smooth/blues sounding amp? If you had to describe something that sets the two designs apart what would it be?

Thanks again, looking forward to trying some of your ideas!

jamie

[Tubenit]

Plexi 25w reverb vs. Carolina Blues Rocket

"I'm really interested in both of these ideas. I'm assuming the more "marshall" of the designs crunches a little better while the Carolina amp probably is more of a smooth/blues sounding amp? "

Yes, that is accurate. I rebuilt a friend's JCM900 into a Marshall Plexi 50w & compared the two side by side. The Plexi 25w reverb had a pretty similar sound but broke up a little sooner being cathode biased and with a paralleled V1. Pretty decent crunch and overdrive.

The CBR is a smoother blues tone. Note some of the similarities between the CBR and a D'Lite build preamp and tone stack. I can still get a very clean sound using the switches and with humbuckers, I can overdrive it right into feedback if I want also. Having one less gain stage than a D'Lite also made have made it less prone to oscillation problems. Anyhow, I enjoy the amp alot.

I should add either cathode biased amp will run JJ 6V6's or 5881's simply by changing the tubes without having to change the bias resistor. I always preferred 5881's in the Plexi 25w but currently am running 6V6's in the CBR.

With respect, Tubenit

[txstrat]

If I got you right, is has to be several sounds in one amp.
I once built a champ II clone with slight modifications and this amp is the most versatile I've ever played (keeping in mind, that this is a one channel amp).
I built it with cathode bias and added a mid control to the tone stack. Also I made the third preamp stage to be switched in and out of the circuit with a DTDP switch.
The amp can be sweet like blackface, growl like tweed and sing like a mesa boogie depending on the vol control, mid boost and the setting of the mid pot. Although I built it with a 18w OT only it can be LOUD in each and every case of settings.
The circuit itself contains not too much parts and therefore could be finished until xmas.
Highly rcommend this circuit.

Hope this helps

Matt

[imaradiostar]

thanks Matt- I'm working on prototyping something very similar to the design you sent me so maybe I can just send it home with my friend for Christmas and see if his Dad likes it.

I was kinda leaning toward a little higher output power so I could put a little more hurt on the 4 10" speakers but it's worth a listen before I make any final decisions.

I hate that I have so many projects, most of which are half finished.

jamie

[imaradiostar]

Oops- I think I may have confused Matt with Matt from musicpowersupplies.com. If so then I'm sorry about that. I appreciate your input. Once again...too many things to try and not enough time to try them!

Question on your Princeton style amp- have you ever tried something of that flavor but with EL84 outputs? For years I've been convinced I want to use this pair of small matching power and output TF's to make a pair of princeton reverbs but I'm starting to think I might prefer something more like the early all-tube Vox Berkeley/cambridge amp (like a deluxe reverb with el84 outputs and one less gain stage).

The truth of it is my friend's dad will probably be happy with nearly anything I build for him as long as it's solidly built and somewhat versatile. I was just hoping to use the nice head and cabinet that I already have finished and a shiny new chassis I just bought on ebay.

jamie

[txstrat]

As far as I'm concerned I'm not into EL84 very much. But that's a matter of taste. I myself like the sound of 6V6 most, straight followed by 5881/6L6.
The JJ 6V6s pair in my champ II clone is smooth when you want it that way and grainy when you need it.

hope this helps

Matt