Boosting Tube amps?

[Captain Chunkulus]

I have always been curious as to why a boost pedal makes such a huge difference in the tightness if you will of a tube amp.. Always wondered if what a boost pedal does could be built into the first stage of the amp instead of just using a pedal. Any Ideas,comments etc...

 

[Kapo_Polenton]

It's been done many times... Yngwie sig. MArshall, Si8lver Jubilee, Randall nuno sig head etc.. boost or OD built in and it does tighten the low end. Some people prefer it without so there is more of a market for after the amp effects rather than those built in.

 

[Captain Chunkulus]

So what was the circuit that was built in? Was it passive, diode clipping etc?

 

[Gainfreak]

I have always been curious as to why a boost pedal makes such a huge difference in the tightness if you will of a tube amp.. Always wondered if what a boost pedal does could be built into the first stage of the amp instead of just using a pedal. Any Ideas,comments etc...

A lot of why a boost pedal makes a difference in the tightness is because it acts like a filter and rolls off the boomy bass that some amplifiers have and some add a bit of treble which will tighten up the sound to as long as you adjust the amps eq controls. A boost also hits the preamp tubes harder so it adds gain and compression which will also add to the sound and feel of the amp.

With that said, Marshall tried to do this with the 2205 and 2210, jcm900 and jubilee series of amps but they missed the mark on the level of boost because Im sure at the time they didn't know how to squash the noise that is added with a boost IMHO. The new Marshall Kerry King and YJM both have this concept built into the amps along with a gate to squash the noise thats added and I believe ,but could be mistaking, that the Blackstar amps have something like this going on but not as extreme as the KK or YJM.

 

[Shiny_Surface]

I've read from numerous sources that a boost pedal through the front end of an amp is not exactly the same as having diodes built into the signal path, not sure how accurate that is but I tend to believe it from my own experiences.

You may like it though.

I have an early JCM 900 mkiii head where the gain sensitivity control is basically a diode control. With the gain sensitivity on 0, the diodes are out of the circuit and the amp sounds quite close to a single channel JCM 800 with the preamp gain wound up the amp gets a nice medium gain crunch.

Then as you turn the gain sensitivity up the diodes kick in and you get more gain (and added warmth I've noticed).

But if I have the gain sensitivity on 0 and use a pedal to boost the front end instead, it sounds different.

Obviously that's just one example but in this case while both methods can sound good they do sound different.

 

[blackba]

I have always been curious as to why a boost pedal makes such a huge difference in the tightness if you will of a tube amp.. Always wondered if what a boost pedal does could be built into the first stage of the amp instead of just using a pedal. Any Ideas,comments etc...

A lot of why a boost pedal makes a difference in the tightness is because it acts like a filter and rolls off the boomy bass that some amplifiers have and some add a bit of treble which will tighten up the sound to as long as you adjust the amps eq controls. A boost also hits the preamp tubes harder so it adds gain and compression which will also add to the sound and feel of the amp.

With that said, Marshall tried to do this with the 2205 and 2210, jcm900 and jubilee series of amps but they missed the mark on the level of boost because Im sure at the time they didn't know how to squash the noise that is added with a boost IMHO. The new Marshall Kerry King and YJM both have this concept built into the amps along with a gate to squash the noise thats added and I believe ,but could be mistaking, that the Blackstar amps have something like this going on but not as extreme as the KK or YJM.

The Marshall 2553 silver jubilee I have still sounds good with the Maxon Od-808 boosting the distortion mode. Never tried boosting the rhythm clip though.

I am going to have to try cranking the input gain low and boosting that.

 

[Gainfreak]

I've read from numerous sources that a boost pedal through the front end of an amp is not exactly the same as having diodes built into the signal path, not sure how accurate that is but I tend to believe it from my own experiences.

You may like it though.

I have an early JCM 900 mkiii head where the gain sensitivity control is basically a diode control. With the gain sensitivity on 0, the diodes are out of the circuit and the amp sounds quite close to a single channel JCM 800 with the preamp gain wound up the amp gets a nice medium gain crunch.

Then as you turn the gain sensitivity up the diodes kick in and you get more gain (and added warmth I've noticed).

But if I have the gain sensitivity on 0 and use a pedal to boost the front end instead, it sounds different.

Obviously that's just one example but in this case while both methods can sound good they do sound different.

I agree with you. The concept is there on the older models but there is most definitely a difference between the diode clipping and a boost circuit before the amp. I think they got the idea of using Diodes in the older amps to heat up the amp like a TS but its most definitely different now that I think of it. Well Im not sure if they got it from a TS idea as it was an old trick back in the day that a lot of modders knew. The later models like the KK and YJM are using a boost circuit before the amp just like if you were to boost it, which is why they added the gate .

 

[Gainfreak]

I have always been curious as to why a boost pedal makes such a huge difference in the tightness if you will of a tube amp.. Always wondered if what a boost pedal does could be built into the first stage of the amp instead of just using a pedal. Any Ideas,comments etc...

A lot of why a boost pedal makes a difference in the tightness is because it acts like a filter and rolls off the boomy bass that some amplifiers have and some add a bit of treble which will tighten up the sound to as long as you adjust the amps eq controls. A boost also hits the preamp tubes harder so it adds gain and compression which will also add to the sound and feel of the amp.

With that said, Marshall tried to do this with the 2205 and 2210, jcm900 and jubilee series of amps but they missed the mark on the level of boost because Im sure at the time they didn't know how to squash the noise that is added with a boost IMHO. The new Marshall Kerry King and YJM both have this concept built into the amps along with a gate to squash the noise thats added and I believe ,but could be mistaking, that the Blackstar amps have something like this going on but not as extreme as the KK or YJM.

The Marshall 2553 silver jubilee I have still sounds good with the Maxon Od-808 boosting the distortion mode. Never tried boosting the rhythm clip though.

I am going to have to try cranking the input gain low and boosting that.

I love the tone that I get with my 2205 with a ts808 in front of it! I use it that way most of the time and is sounds prettey amazing IMHO. Well either that way or with an EQ in the loop with the level maxed. Sounds pretty cool

 

[Mark Day]

The Boss OD mod for your Marshall

\

and powered bt Archer!!!!

 

[Gainfreak]

The Boss OD mod for your Marshall

\

and powered bt Archer!!!!

AMAZING!!

 

[primerib]

boosting compresses the signal, therefore making it "tighter". but some of us (me) love rogue low end frequencies flying about.

 

[Bloodrock]

The Boss OD mod for your Marshall

\

and powered bt Archer!!!!

Holy shit dude! Someone actually did that???

 

[Captain Chunkulus]

Thats just wrong..

 

[Ventura]

boosting compresses the signal, therefore making it "tighter". but some of us (me) love rogue low end frequencies flying about.

Here here!! That'd be me too

Love the bass... I typically never use an OD in front of my tasty amps, just a CLEAN boost, which drives the snot outta the front end, but doesn't compress or clip any of the yummy thunder

Mo

 

[Milerky2]

Clean boosting the front end of a gain stage is what made Randall Smith famous. By cascading the gain stages you increase the voltages across the entire preamp. This modification on Fender Princeton Amplifiers is how the Boogie Mark 1 was born.

And Mesa/Boogie was born... and boosting within the amp was accomplished.

 

[glip22]

Clean boosting the front end of a gain stage is what made Randall Smith famous. By cascading the gain stages you increase the voltages across the entire preamp. This modification on Fender Princeton Amplifiers is how the Boogie Mark 1 was born.

And Mesa/Boogie was born... and boosting within the amp was accomplished.

And Carlos walked into a music store where Randall was at or something similar and played one of the modded Fenders. He said man this thing Boogies. And so it was born.

 

[dstroud]

The Boss OD mod for your Marshall

\

and powered bt Archer!!!!

oh man, I always wanted to do that!

 

[JakeAC5253]

Clean boosting the front end of a gain stage is what made Randall Smith famous. By cascading the gain stages you increase the voltages across the entire preamp. This modification on Fender Princeton Amplifiers is how the Boogie Mark 1 was born.

And Mesa/Boogie was born... and boosting within the amp was accomplished.

Wasn't Jim Marshall the first to cascade preamp tubes to create preamp clipping? I could be wrong, but that's what I thought anyway.

 

[warren]

I use an mxr 10 band eq to boost mine. Great thing about that is that it's got a volume slider for the actual boosting and then you can boost and/or cut different frequencies for different guitars and dial in the exact tone you want. Plus it's a clean boost. I find that using a tube screamer (or any OD pedal) adds a grainy effect that I don't particularly like.

 

[Digital Jams]

Only reason I hit an amp with a boost these days is for feel and added sustain during leads, I use a modded YJM 308 with the gain on zero and the level about 3/4s. I use it while using the jvm in crunch mode or the 77 JMP 4 hole.

My amps already have the tone and gain needed.