Questions about the Studio Preamp

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metalyca88

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Hey all!

I recently obtained a Studio Preamp as my first real amp, after about 10 years of playing with modelers, and I have some questions that I was unable to find a direct answer for online.

1. Exactly how close is the Studio Preamp to the IIc+ Preamp? I've seen posts saying it's 90% of a IIc+ Preamp, but I specifically want to know what the exact differences in the circuit are that deviates it from a IIc+. How can one make it sound like a IIc+?

2. What years were these made? I tried to do a little digging online but it appears that production was August of 1988 - ??. I personally have one with a serial number of SP6750, so I assume mine was made pretty late in the game, but I'm not sure what timeframe it would be in the ballpark of.

3. Were there any changes made to these during production? If it's true that these are 90% of a IIc+ preamp, would any changes have been made during production that would have made it further from or closer to a IIc+?

4. What cool tips and tricks should I be aware of when playing around with it?



Thanks in advance!

~Aly
 

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I just realized I posted this in the wrong sub.. I apologize.. please move, thanks!
 
Hey all!

I recently obtained a Studio Preamp as my first real amp, after about 10 years of playing with modelers, and I have some questions that I was unable to find a direct answer for online.

1. Exactly how close is the Studio Preamp to the IIc+ Preamp? I've seen posts saying it's 90% of a IIc+ Preamp, but I specifically want to know what the exact differences in the circuit are that deviates it from a IIc+. How can one make it sound like a IIc+?

2. What years were these made? I tried to do a little digging online but it appears that production was August of 1988 - ??. I personally have one with a serial number of SP6750, so I assume mine was made pretty late in the game, but I'm not sure what timeframe it would be in the ballpark of.

3. Were there any changes made to these during production? If it's true that these are 90% of a IIc+ preamp, would any changes have been made during production that would have made it further from or closer to a IIc+?

4. What cool tips and tricks should I be aware of when playing around with it?



Thanks in advance!

~Aly
SP5678 here…mine has what looks like the initials JN and 4/15/91 written in black marker on the circuit board…assuming that is the build date that could help in dating yours. The Mesa date my amp site isn’t very helpful with the Studio Pre manufacturing dates as you pointed out.

I can’t answer your questions about how close it is to a IIC+ but I can tell you that with my 50/50 power amp there aren’t many tones I can’t get….from bold crystal cleans to some of the best distortion sounds I’ve ever heard. It takes time to dial it in. Be patient and you will be richly rewarded.

I highly recommend thoroughly reading through the manual, especially the sections where they describe the tone controls. Also try out the settings they recommend as starting points.
 
Thanks for the reply! I've been getting some pretty awesome tones out of it with some IR's so far. Fiddling with modelers has kinda taught me how the different knobs shape the tone on the Marks, so it was pretty easy to pick up. I'm using the SEND out instead of main or recording outs straight into my 2i2. I've thought about having possibly in the future getting a power amp, but I don't have any cabs. Is using a power amp any better for IRs than without? I was thinking that a power amp + a load box would set me back quite a bit extra. Probably more than what I paid for the SP.

At some point I'll see if I can't find a manufacturing date on the inside, and I'll be sure to check out the manual.

Thanks for the info!!!
 
I don't have a Studio Preamp, but I can share my experience with the Quad. I didn't have a power amp when I first got the Quad, so I plugged it into the return of my .50 Caliber (EL84/6BQ5). It sounded ok.

Sometime later I found a 50/50, and then one of the cheaper Marshall 4X12 cabinets for the solid state amps. This was a huge improvement.

The Boogie Half Back cab really took it to another level, and when I got my second cab loaded with EV's on the bottom, the quest was complete.

There are many different versions of the Mark IIC+, so trying to replicate it might be futile.

If you are trying to replicate the Metallica sound, I think the Studio preamp is a good choice. The 50/50 power amp was recommended by Mike B., and a proper Marshall 4 X 12 should get you there.

Disclaimer: This is from an old dude that doesn't believe in modelling amps. When I bought these components, rack mount equipment wasn't in vouge, so it was cheap. Prices have risen significantly since, but keep an eye out for bargains.
 
Hi there,

This is my very first post over here. So i will do a small introduction about my self and then i will move to answering the main question.
I have studied electronics in university and I was a professional quitar player in the past. I have been playing boogies since the very first moment that tried a Mark IV at a music store and that was over 20 years ago. At the same time I got into repairing boogies and other tube guitar amps, so I believe that I have a good knowledge on what is going on, circuitwise and soundwise on each tube amp.
Now to answer some questions.

1a. The topology is like 90-95% the same as the IIC+. What this means is that both circuits, if you take a look at them without taking in account the values of the components, are about 90-95% the same. The differences is that the Studio Preamp has what i call a "Main Section" which essentially is the driver circuit for the amp that you are going to use. This section and especially the "Recording Out" changes the tonal characteristics of the preamp, it changes the frequency range of the preamp, even when you dont plug in the "Recording Out".
1b. The component values are like 90% the same as the IIC+. Those differences change the frequency and dynamic response of the preamp but since those are simple components, like resistors and capacitors, this means that by changing them you can get closer to the sound of the IIC+.

2. I think they started making them at around 1988. Mine is SP1655 and has 3-1-89 written on the PCB.

3. From what i have seen over the years, boogie did a couple changes on the PSU components. Those changes do affect the response of the whole circuit, but not so much as the changes between the IIC+ and the Studio Preamp components in general.

Yes you can change the components of the Studio Preamp, in order to bring it closer to the sound of the IIC+ but it still wont be a IIC+. As i said in 1a, the topologies are close which means that they are different. Personally i went down that route, to make my Studio Pre sound like a IIC+, and it was more than just changing components. I had to change the route of the signal, even the reverb circuit, in order to get closer and closer to the IIC+ circuit. I had to do a couple changes on the PSU also to get the voltages closer to the IIC+ range. And since one change brought another change I decided to add another potentiometer for the LEAD VOLUME, to have separate volumes for clean and rhythm channels, do a mod to the BASS potentiometer in order to have different range on the clean channel and different range on the lead channel. What this does is that on the clean channel you can dial the bass up to "10" while at the lead channel the "10" dial equals to like "3" or "4", so I can get pretty tight sound on the lead while I get some good lows on the clean channel.
At the end the studio preamp will never be a IIC+ because it doesnt have the power amp section of the IIC+, which, i would say "interacts" a lot with the preamp sound and the voltages. Of course you can use a 5050 or 2:90 which are excellent power amps, BUT the PSU section of the power amp will be different from the Studio Pre PSU section.
In overall the Studio Pre is a great piece of equipment and it has a great sound on its own. You can go from great cleans to those great boogie lead sound. It just is a biiiiit different than the IIC+. My personal Studio Pre, which while i modded it to be the exact IIC+ preamp, dont know how close it is to the IIC+, but what matters to me is that, the way it sounds now, it is what i want and fullfills all my needs. It has great cleans and the lead is that organic sound of the IIC+.
 

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