Best overdrive should be in your amp..

[Mr. 80's]

My Carvin Belair has a drive channel that sounds like a DS1, it's all diode clipping

My Bugera G5 has a drive stage that again sounds like diode clipping

My Laney GC80A is solid state and it drive stage is most likely diodes as well

Amp makers have been putting in overdrive pedals for the drive section for years now

It may not be the flavor you want.
but they are in there.

Peavey does this as well with their tube amps
tube distortion is a myth

Most manufacturers use pedal circuits to boost the signal to the tube already in the amp
same as the pedal guys do

But none of them are actual built in pedals though like OP is talking about. Just because they are using opamp, diodes or LED for clipping doesn't mean they are actual pedals built in. Modelers don't count either.

 

[PFDarkside]

With the multitude of overdrive pedals available, building one in seems to “lock” you into a specific sound.

Overdrive, Boost, Fuzz, Distortion, many different ways to hit the front of the amp differently. Different EQ, compression, clipping, etc.

Also, I used to be in the “tube amp clipping is best” camp, until I actually played a bunch of other things. A Tube Screamer hitting a Fender tube amp sounds absolutely fantastic. It pushes the first gain stage, focuses the signal with more mids, less bass, and adjustable cut in the tone control. Only a little bit of clipping, you aren’t really looking for the distortion of the TS onto a crystal clean amp, it’s the interaction that makes it great.

 

[Lewguitar]

Of course there are none with built in pedals. A pedal would be outside the amp not in it.

 

[JB_From_Hell]

For me, Boost/OD/Distortion/Fuzz are all such a personal preference that I'd hate to be "stuck" with the one built-in to an amp. Or, be stuck with just one. So for me, outboard is the way to go.

Agreed. Surprisingly, I can plug straight into my Fender Frontman 100 and enjoy the onboard drive and boosted tones, but when I put a Wampler Dual Fusion in front, it really starts getting fun. Or the Chicago Stompworks TS/Maestro box... or my SolidGoldFX Beta... or my modded DS-1...

 

[ehdwuld]

If an overdrives pedal circuit is "inside"
I consider that

Pedal inside
Just saying

Semantics that differentiate between pedals and amps are just that

Amps with drive sections
Do so with clipping circuits similar to pedals

 

[Mincer]

This is probably why I always liked power amp distortion better than diode/LED/preamp (although I use those too). Power amp distortion isn't practical in a lot of situations.

 

[Snake Aces]

For some reason, when I find an amp with killer overdrive/dirt whatever, I hang on to it forever.

Some of my favorite built-in dirt amps are the Traynor Custom Blue 50 (with stock tubes or KT77s but especially KT77s), Laney's Cub12, almost every Marshall I have ever played or owned (sold these years ago... big mistake), a lot of premium Fender amps (especially Hot Rod Deluxe), anything from Mesa, almost anything from Orange and now... my H&K GM 40 Deluxe as well.

When it comes to amps, premium models are worth every penny, but I do consider the Traynor and lower end Laney stuff to be stellar for the price.

 

[Ascension]

My old Marshall head (JCM900 MkIII) had a diode rectifier in the pre-amp stage somewhere between the first and second preamp tube. It may have even been between the first and second half of the V1, can't recall without looking at the schematic. It was kinda like an overdrive built in. Had it's own gain knob (went from 11-20, continuing from where the preamp gain 1-10 left off). Killer sounding amp and the way it was designed really made it work great. Nothing was lost.

Yep owned several of those over the years GREAT amps! One gain was all tube the other added the clip diodes. With the tube side only it sounded like a JCM 800 and the diodes was like using a really good pedal. trick was to find the right balance between the 2.

My 1991 Carvin X 50 B factory Hot Rod Mod head is similar. Has a push pull on the gain that drops a 20 DB gain boost with clip diodes in when it's engaged. Sounds like a good JCM 800 Marshall on just the tube gain then is very Soldano like with the Hot Rod Mod engaged. There are many amps out there that are like this the JCM 900 SLX is another good example. It's based off the MK III JCM 900 Dual Master just adds another tube gain stage.

 

[Erlend_G]

I'm getting a great, "unique" and ... inspiring tone;

by running my Electro Harmonix "Octavix" fuzzbox, set at moderate settings- into a medium-gain OD channel of my Blackstar Ht-20!

It makes the sound gnarly, saggy- blooming... violin-like! I like it so much, I can't use the amp/OD channel alone, without a touch of the fuzz pedal infront!

-Erl