Formula questions

[tim6string]

I have a Mark IV and love it. I plan on keeping it.

I have been looking for a backup/Blues type amp. Granted the Mark IV will work great for that as well.

I was thinking about getting a Formula preamp. The prices are not yet out of hand and they look like nice little preamps.

I have a simul-satelite for a mono tube power amp (it would probably make a killer preamp for that) and a simul-stereo 295 power amp as well.

Anyone have one of these and can recommend it as a decent alternative/Backup. I also have a keely mod TS-9 I could put in front of it if I needed the gain, but I am thinking I won't need that.

All thoughts and opinions welcome.
I wanted a quad, trying to avoid the cost (it won't be my main amp) and I wanted to avoid having to get a bigger rack.

 

[Fernando]

Hi! I've got en early F-Pre (#FP-000049) that I did the "Andrew mod" to, and i like it quite a bit. That mod smoothed out the high gain and made it sound a little more "airy", with more breath. Since my F-Pre is an early model, the schematics did not match the ones that Andrew used so I ended up only changing 1 resistor, but that was enough to change the sound. Your milege will vary. I'm also using it with a 295. Sometimes it can get "buzzy" if the highs are boosted too much. I also have a MKIII that has been modded to the C+ with the R2 volume. Obviously the MKIII has my heart. I use both in a dual rack setup, so I have each setup differently sonically so that when I mix them or run them separately, I get a cool mix of sounds. It also has a smaller footprint, so rack wise, you will save space. Sometimes the fact that Lead 1 and Lead 2 share the tone controls can affect the possibilties for tweaking your sound; but you can setup the EQ so that it only works with Lead 2, I use this option. Price wise, I have no idea what they are going for used, but, I imagine that they would be less expensive, and easier to find then a quad or studio. Maybe some other members could chime in on this part of the topic. Ebay may be a good place to do a quick search to get a general idea of prices and avaliability. Good luck!

 

[tim6string]

Thanks for the info. I was thinking about ultimately going the route you mentioned, using both.

I currently have a Rocktron Voodu valve preamp that I am using and it works nice. I have to believe the Formula would blow that away.

 

[matthewl0799]

New to the forums. Just wondering if anyone could tell me how to get all the information I need to do the andrew mod? Love the Formula's clean channel, but the god awful muddy lead channels need some work. Any info would be greatly appreciated. Been searching the web for quite a while, hope this is the place. Thanks!

 

[disassembled]

New to the forums. Just wondering if anyone could tell me how to get all the information I need to do the andrew mod? Love the Formula's clean channel, but the god awful muddy lead channels need some work. Any info would be greatly appreciated. Been searching the web for quite a while, hope this is the place. Thanks!

My personal advice is before you rip out the soldering iron is to go tube shopping. Chat with Bob at Eurotubes if you want some current manufactured tubes. If you want to totally change the character of a certain channel you can probably do it with a simple, pain free, easily reversible tube swap. Trust me, I've been down the "if I just do one more circuit mod it will be exactly what I am looking for" route and never wound up happy. Sometimes it's easier to get rid of something than to follow other's opinions.

Here are some tube recommendations:

V1 should be tube buffer input stage and this will be for your clean channel. You want this to have the least microphonic tube since ALL channels will be using it. Your manual should tell you where this tube is located (usually closest to the input so in your case all the way to the right).

V2-5 I do not know the functions of these tubes but they are usually specific to channels (ie the highest gain channel might use V1-3, EQ V-4, Loop V-5) and should be in the manual. Just FYI tube preamps DO NOT have phase inverters only AB tube power amps do.

Eurotubes.com stocks JJ tubes and I have had awesome results using their ECC83 S's and ECC832's. The JJ tubes are considered Linear when compared to the majority of tubes made today. I usually run my mids a lot higher and appreciate the presence that these tubes give my guitar in a mix. The ECC832 is something that gave me control of my high gain amps by reducing preamp gain. This totally changes the feel and for me it did it in a positive way. Pre tubes are dual triode meaning they have two audio paths. The difference with the ECC832 is one gain stage is that of a 12AX7 (the input stage) and the other is a 12AU7(output stage) resulting in a highly dynamic but reduced gain tube. This is good if you run your gain about halfway and feel that 100% is too much or too muddy. On my old triple XXX head I could barely get that nice soft crunch until I did this swap. After the swap I could go 75% on the gain knob without feeling it was too much whereas before 50% was overkill. Remember, most of the recordings you hear are not plastered with pre gain but usually have refined tone shaping and power tube dynamics/compression.

Good luck!

 

[tim6string]

Well I know have a Formula Pre. It is a pretty early model.
I think it sounds great!!!

I thought the leads where a little muddy at first, but backing off the gain made a big difference. I found that you could drop the gain from say 10 to 8 with little difference in the amount of gain but a pretty important difference in the tone.

Still interested in details on the mod, but I was pretty impressed with this little preamp and I haven't even started messing with tubes. It was used and I have no clue how old the tubes are.

 

[gtrnstuff]

I just discovered how Crucial impedance matching is for the Formula and the Recro Pre. IME the Formula wants to see at least 100k from the main outputs or the tone is mud. Most pro processors seem to be in the 25k range for their unbalanced inputs(!!) I fought with this for years and almost sold it. MESA does refer to this in the manual, but more as it relates to using main and recording outs at the same time. Wish they'd have posted actual specs.

 

[tim6string]

Not sure what you mean. The spot in the manual talks about a volume drop using both outputs at the same time because there is no buffer, but if you are using 1 out, would that make a difference?

I am assuming you found something that made a difference, just not sure what exactly could be the cause???

I gigged with the Formula this weekend, small gig so I used my Lee Jackson SS SP1000 power amp. I ran the record out into my GMajor and effects, then into the power amp stereo. This little preamp rocks. For the stuff we are doing (more 80s metal) I thought the Formula was a little more agressive and appropraite than my Mark IV. I loved the sound and I didn't even have the my Simul-295 at the gig.

 

[gtrnstuff]

It sure made a difference with my rig. YMMV. See my new thread that I think I named "preamp output impedance".

So you used the record outs, not the main outs, through a poweramp and guitar speaker? Haven't tried that. Seems like the speaker sim into a speaker would stack up a little odd, but I'll take your word that it was great. The record outs might be less mismatched than the mains in that setup,too.

 

[tim6string]

I tried it that way in order to get some of the power amp feel and hoping it would help with the Solid State power amp. It seemed to work great.

I will have to try it the otherway as well.

I did run the standard outs to my 295 and thought it was great, but I had no processors in the mix so the impedance matched to the power amp. But that is also where I noticed the touchy gain setting adding mud.

But I will keep that in mind when I go standard out to the GMajor.

It is good to understand as much as possible.

 

[gtrnstuff]

I tried it that way in order to get some of the power amp feel and hoping it would help with the Solid State power amp. It seemed to work great.

I will have to try it the otherway as well.

I did run the standard outs to my 295 and thought it was great, but I had no processors in the mix so the impedance matched to the power amp. But that is also where I noticed the touchy gain setting adding mud.

But I will keep that in mind when I go standard out to the GMajor.

It is good to understand as much as possible.

I just tried it your way, with the recording out (EQ toggle down/hi-gain) feeding my mixer, power amp and cabs. Actually pretty fine, sort of does the V shape EQ and not too much lows. Helps the Formula escape that low-mid thing that tends to dominate. Who woulda thunk it? Now I know something new.

Also, the G-Major has a reputation on another forum because of its extra-low input impedance. If your Formula doesn't drive it well with the main outs, you've been warned ;-) Interestingly, the FX send seems to drive it just fine.

 

[tim6string]

Now I will have to try the main outs to the GMajor. The recording outs drive it just fine. It will be interesting to see what happens.

I do have more than enough room left on the G to bring up the input and turn the output up on the Formula.

But I was pretty impressed with the Recording out. My plan was to use the recording out with the SS amp and the regular outs with the 295