Great stuff! I feel like a 'bright cap expert' now in only 20 minutes after knowing nothing about them before. Pete is a _fantastic_ educator.

The ever changing quest and adventure to find the right sound . And it does make a difference . Thanks for doing this Pete .

Thank you, Pete! It is so good to see you stepping up!! Impressive…

This was excellent. Thanks Pete for the education on how to blend those channels together. I am always appreciative of your video content and quality.

Always impressed with and appreciate your talent, knowledge, and practical no-nonsense videos, Pete. Many thanks!

Your Marshall sounds like mine. It's my 3rd since I got my first in London in '71 when of all guys Ron Wood was using one and put me onto one he seen from a studio I could get relatively cheap. At 75 I hope this one sees me out, LOL.

Great video! You explained the bright cap in a very easy to understand way and then did a superb job demoing it. Thanks again, these videos are fantastic. 👍🏼

Great video as always! The way I approach it is using the cap to decide the cutoff frequency, as you clearly explained, and using an optional resistor is series to attenuate the signal going through the bright cap, therefore defining the sweet spot of the Volume I. That way, for example, a 500pF cap can sound balanced when Volume I is at lower settings.

Lots of good stuff here. Really a great video to show how the 2 volume pots work together. Thanks Pete!!!

This amp series is always full of knowledge. I love these!

Sounds immensely better with the cap! Invaluable info. Thanks!

Really interesting and well demonstrated (as always) vid, Pete. Thanks for taking the time to do this. I’ve been in two minds about getting into this with my 1987x which I currently use with no bright cap but have the 4700uf on a push pull. I think I’ll just leave it alone now having heard a real world comparison. Rock on!

Great video! I am a huge fan of the bright cap! I know lots of people who remove it on Marshalls… but that’s like a HUGE part of the Marshall sound and a big no-no for me. I just finished a build a few months ago centered on a 1987 (utilizing original 60’s/70’s parts, Piher resistors, Mullard caps etc), but instead of having the “normal” channel, I added a switch to route the bright channel into v1b, so it switches into a 2204 (even switches a master volume in/out). But for this amp I wanted more control on the bright cap - it can get a bit raunchy (depending on the value) when you start dialing the gain back, so I came up with a unique (at least unique to me) mod for this… As per usual, I connected that output of stage 1 to the GAIN (1MΩ) pot input, then from there I connected my 1000pF cap to an input of another (dedicated) 1MΩ pot. Then the output of that additional pot gets wired back to the GAIN pot’s output (middle lug). So it’s like having a bright cap in it’s usual place (between the input and output lugs) with a variable resistor in series with the cap to allow me to control the amount of bright cap that is passing to stage 2. Sort of a blend knob I suppose? It’s great for when I want to dial the GAIN knob back to 5, I pull that additional pot (“tone” pot) down to 5 or 6 so it still has that bright Marshall sound, just a bit more useable in my opinion.

0.0047uF (microfarad), 4.7nF (nanofarad) and 4700pF (picofarad) are all the same thing if anyone is getting confused. It might actually help you find a certain brand/type if you want to purchase one for your amp. I like Class 2 Z5U dielectric 1000vdc ceramic capacitors as bright caps in Fender and Marshall amps. Polystyrene and silver mica caps are also popular choices. 500vdc or higher is a good safety margin for AC service, even though bright caps in this position will never see anything over 100vac.

Pete, thanks so much for sharing your knowledge. So cool to learn from you.

Those crazy nights i do remember in my youth…. One of my favorite opening riffs- Great video Pete! - 👏🏻🔥

Tried this mod on my JTM45 for about a week and then had my tech take it back off. Just kills the warmth of the tone IMO. I kept preferring the sound when you had it turned off and the treble and presence pushed a bit more. That sound is what makes those amps incredible to me. All good tho, still learned something.

Great job Pete. Man I love that Schon riff. So good 👍

Great video as usual and bonus points for the "Stone in Love" intro. Will always love that song.

Great video as usual! And EVERY setting you played sounded great -- as usual!!!!!!

Excellent Video Pete!!!! Great playing and tones, and man I never knew so much about the BC, till Now!! Stay Groovy and Keep on Rockin' Bruddah!!

That is the cleanest I've seen the LP Custom look. Great tones.

That Suhr sounds pretty amazing in any configuration!

Cool that you shared your capacitor experiment on the YT, It does provide insights otherwise I'd not indulged.

This is the video I was waiting for!! Very helpful. I swapped the bright cap on my plexi 10000 times. Now I settled with a 100pf but the switch is the best solution!

I had a PC board JCM 800 and it didn't sound great... Using my electronics and electrical background knowledge, I tore it apart and built a point to point wired JCM 800 along with custom wound mercury magnetics transformers... What an amazing difference!!! Then I played with caps and pots and installed a cap switch knob for exactly this reason. That exact amp went to Germany with "Jim" whatever his name was (Opening act for Anthrax in Germany that year) and Scott Ian asked if I could make a 100W version.. hence I began building 6-50W and 6-100W "Marshall" amps and experimenting with the 'Plexi" circuit which was good but... a little tweaking and WHOA!! it breathed FIRE!!! Anywhoo, cool video that brought back some memories of tweaking amps with just different pots and caps! Cheers dude! (1st 50W amp took 40 hours to build and another 40 hours to tweak on the scope!)

Thanks for sharing your knowledge, experience and thoughts on this capacitor subject

Great video. I understand MUCH more about the bright cap now.

It sounds awesome. Great playing as usual.

Awesome stuff Pete! Thanks!

Great video Pete! I do enjoy these geek outs with old Marshall's. Personally I am a fan of no bright cap in my amps but run the treble and presence higher. The Suhr is cool but that old '72 is KILLER!

HOLY MOLYYY! that guitar sound of stone in love was spot on! so good!

Such a great (nerd) video!! LOVE IT!!! Thank you for putting together such cool videos like this. Really enjoy listening to you talk about amps (music gear in general)!!

Awesome! I have a '86 Model 1987 50 four hole. Now I'm going to check my bright cap! Fun.

Very informative Pete!! Thanks for sharing!!

Pete, I find your videos so interesting in that although I don't know much about the electronics of amps or guitars, I found it to be instructional.

Very interesting and useful information thanks P.T. 🙂

Fantastic video. It is helping me get familiar with a new amp that also has a switch that allows you to choose between three bright cap settings--one of which is no bright cap. Super helpful examples/tones--thank you!

Thanks for the info Pete. So simple and so effective.

Bright cap makes all the difference.Good idea to make it switched that's what I do on the amps I build. You got it right Bro! Thanks for spreading the word Pete! Good video.

Great topic - really helps to alter the perception about the "dimed" Marshall sound...most recorded sounds you ever hear, are in that "sweet spot," somewhere below 8 on Volume 1. Great video! Thanks Pete!

Great vid. I think a lot of people don’t have a good understanding of this subject thinking a lower value bright cap will have less treble when a higher value will actually sound better because it lets more high mids through. I just changed my 470 p. to 1nF in my Ceriatone 2204 and now it sounds like a Marshall.

Cool video Pete, the Suhr SL68 sounds amazing!!

Very cool demonstration, Pete. I'm glad that you like and played "stone in love". The song is simple but brilliant and the reason I picked up the guitar. Neal is a ferocious guitar player when he wants to be and it shines through in this song. The solo is to me, still the epitome of what a great "song within a song" solo should be along with a monstrous guitar tone :) kudos my friend

Suuuuuuuuper interesting! Thanks for doing this, Pete. And, damn it, now I need to put in my '74 California Jam DVD. Can't get that last riff out of my gourd.

wonderful explanation and demo,love it!

Great vid, knowledge and playing! Thanks!

Thanks for the tips Pete!

I dig the no cap with the treble and presence up.

Sounds great!

Always enlightening.

You can easily make a "cap switcher" box to determine which value sounds best in your particular Marshall.

Great video Pete! I'm almost always a no bright cap guy.

When I build amps, and voice them at the end, I spend the most time with the treble cap on the volume and mixing resistors bright caps. They get the excitement in the sound, but must be voiced for the volume you expect to play at, which is difficult. That’s why I have often put three way switches in for my amps for the caps.

Thanks for using analogies I can understand. New to all this stuff finally understanding the “high pass” thing but your “transistor radio” comment made my 54 yr old newbie brain go 💡

Cool vid! Also, that's one awesome looking Les Paul!

I experimented with this a while back and tried something I haven't seen anyone else describe. I left the original cap in place and added a potentiometer to control how much signal was getting to the cap (I think I placed it in series but I don't remember for certain; but parallel should as well). So I was getting the same frequency cutoff but could control the signal level. I found this to be so effective and satisfying (and especially useful at different volume levels) that I considered for while installing the pot permanently in the amp. (Maybe replace Presence with a concentric pot (two pots in one) to avoiding drilling?) I remember thinking that it was actually more effective than the Presence control.

🌟🌟🌟🌟🌟 luv the 4700 pf.

The bigger cap sounds great, but no cap gives you fantastic cleans. I think I'd just clip it. That's a nice mod though!

4700-5000pf is also the value used in the Dallas Rangemaster treble booster. It acts very much in the same way, letting through a lot of mids and not just treble frequencies and is a very guitar friendly range. Makes perfect sense that it works in the Bright Cap function as well

Great video Pete! This is a very useful component, you can keep it there and it may benefit to your sound or you can cut one leg of it and you've got a sound that you'll like a lot more! My take on this: on Marshall 2204 or 2203 I cut one leg of the 1nF (0.001uF or 1000pF) and get a (to me) more useful tone over a wider gain range. On Marshall 1959 or 1987 I take the 4,7nF (0.0047uF or 4700pF) from the bright channel and put it on the normal channel; may put a 100pF on the bright channel instead. A JTM45 or the like often got a 100pF cap on the bright channel; a 4,7nF in parallell with that is very cool; crunches it up but keeps a lot of warmth in that amp.

Thanks Pete

Cool video. I know more about Marshalls amps and bright caps now!

okay I use to work for Martin and I make music and help Musicians Globally and I really dig what you did here. Pretty cool. I'm on your team totally

Hi Pete! 👋 Thanks for sharing experience! I have removed that little perpetrator long time ago ,and yet amp was still horribly bright! I know most of people owning JMP’s suffer that problem, and most likely that is why they are here, so i would like to share with them my experience! 🙂 👋 In my case it came up to be the wall voltage! My problems began when I moved in my new house! In the place I lived before was 112V~115V! My new house was ~124V! Well someone will say few volts , does it really matter! Well it definitely did in my case! But hey! I recapped, retubed my amp ,learned how to bias it, and even thing or two more! So I have gained many things from that unpleasant experience! Everything really changed when I bought one of these things called “Variac”! People usually use them to get the so called “brown sound”! No! I did not buy it for that, but still I could use it to get that sound too! And no , It is not one of these bank busters sold for arm and leg! This one was like $60 shipped, and it was around 20A! So there was plenty of current! There are many demonstration videos around here for them! People use them for different things! But be aware! It is big, bulky and heavy piece of hardware! And another important thing ! The readings on the scale and the actual voltage are way off! So don’t count on it! I have nice meter plugged in the second socket to have the actual readings right! And let me tell You! Everything came where it should be! Ass soon as I dropped the voltage between 110V~115V, amp came to its glory! No more piercing sound, and EQ start making a lot of sense and use! So, the higher the voltage, the brighter and brittle the sound become! I have found another thing! My guitars have also voltage preferences! One of my guitars absolutely love around 108V, while another comes at its prime at 115V! I did not try to put back the bright cap tho 😅 Well hope my experience help someone’s struggle of his life! 😉 All best to all, and Happy Holidays ! 👋

add different tubes in the p amp and power tubes, different pup's, cord attenuation, dirty power, mismatched speaker loads, and pick attack and position, and * and it's all good for now.... GREAT stuff Pete! oB

I have an older Peavey classic Amp . It has a Brite Switch I love it !!

Love this vid. Plexis rule. Very informative and helpful

Top notch. You should get in touch with the TPS lads and get 'em to mod their Marshall, which they've been meaning to get done for ages.

Hit the like button in less than 10 seconds for that opening riff. Stellar playing as usual.

Years ago I lifted one leg of the bright cap in my 77 JMP and it completely transformed the amp for the best. The other leg is still soldered on, so if I sold it and the buyer wanted the cap in, you just bend it back into place and solder it back in place.

EE chiming in here.... One way to view this cap in parallel with the pot is that it is a frequency dependent resistor. The capacitor "resistance" is known as the reactance. The formula is Xc= 1/ (2 * pi * Freq * C). where pi is 3.14, Freq in Hz, C in uF (1e10-6) or pF (1e10-12). The result is in ohms. Another thing to remember when placing resistors in parallel is the combined resistance is always lower than the lowest resistor value. So if the bright cap resistance is getting lower then it dominates the signal path and routes the higher frequencies around the pot. Lastly, if possible use a metal film capacitor type vs. a cheap ceramic as the bright cap or (bleed cap in the guitar). There are technical reasons for this but in the end they sonically sound better.

In case it hasn't been mentioned already, this is what Fender did with their bright switch starting in the mid 60s on amps like the super reverb. (they also originated the bright bypass cap as dealt with in the vid on the tweeds the Marshalls are based on)

Awesome video!!!

Stone In Love. Great song.

It’s like many other things in the guitar world ,you have to just dial it in to your situation. I tried this on my 71 super lead and it was too bright but that’s just me and my rig you may feel different in your situation… Super great topic… Keep on rockin……

That is one phenomenal sounding Les Paul.

Bad ass - Thanks!

Awesome Pete! I've recently discovered the whole "cap" tone differences in both guitars and amps over the last few years. Makes such a HUGE difference! Your tones here are KILLER! ON A SIDE NOTE: I actually started shooting my video to showcase my old amp that Neal Schon endorsed in the early 90's & you and I played the same Journey and Zep tunes! Oh and I have my black Les Paul! Haha! I think I'll reshoot my opening.

Ive been thinkin about it for a long time Pete i have a 1994 1987 head when i think and you Correct me were Reissued so its been with me since 1994 bought it brand New from Manny,s in New York and it just sounds Awesome so i just will Keep it Stock ¡ Thanks for the Info ✌✌👍👍🎸🎸

This amp mod is like the treble bypass/treble bleed mod you can add to your guitar's volume pot to allow the higher frequencies through the circuit so when you roll off your volume it doesn't get muddy. I do this to a lot of my guitars.

I liked the tone of the 72 Marshall 50w better. I have a 68 (1200 series)Metro/Friedman 100w head that you can switch off the bright cap with Volume 1 which is also a push/pull to switch between bright cap or none. Another great video!!

Damn it Pete! I love man. Way to do a fantastic video about a capacitor (approx value of $1.15)! Seriously, the devil is in the details. Love it. How did you ever decide to do a video on this topic?

This works the same on the tone pot cap on your guitar(if you have one). Great info here as always!

I have learned so much about dialing in a tube amp from your demos. Absolutely invaluable information. Thanks for all you do. Cheers!

It’s also why. a cut control aft the PI works so well

Great video!

I find cool having the option switchable. That 4700 pF is too VH sounding for me. Great for higher gain, but for more applications, having it off makes it smoother and more fitting in a band setting. Just my 2 cents. Awesome video man !

Stone in Love with this video. ;)

WARNING! Valve amps have huge power capacitors that hold a lot of volts (600+). If you touch them when they are charged they will discharge through you and probably kill you! Unless you learn how to use a discharge tool (easily made) and a multimeter to check it worked don't mess inside your amp. Although Pete mentions briefly at the end I don't think it was stressed enough the potential danger involved in opening your amp. I built my own amp (Fender 5e3) so not saying you can't do this but look up discharge tools and how to use them. Also keep 1 hand in your pocket whilst you are using it so you can't accidentally discharge across your chest.

Ooo This is good!

Hi, i tried it on my origin 5, it works well. Thank you.

Great video! I installed a push-pull pot on the volume 1 of my JMP so I can switch in and out. You should really make a video on vintage greenbacks vs new.

When you have no bright cap and turn the amp volume down so that it is clean there is a treble roll off due to the capacitance in the tubes, lots of people like this treble roll off. Using 90-100pf bright cap keeps the top end more level through out the range of the volume control. That is why that value was chosen and used by many since. Adding 680 - 1000 - 4700uf makes the volume control a tone control.

Nice! Just bought an Origins 50 to run my BE od and probably Helix - I’ll check this out

Amazing 🔥

Geekery of the highest order. Love it.

That 72 Marshall is something else.

I love all the tones on my stock 71 1987 from about 3-7 on the bright volume, straight into the top left input no patching. On the lower settings just use the guitar tone controls to tame the high end. Helps that I’m running through a 68 straight cab with Pulsonic Greenbacks as they are nice and warm. Modern speakers or even Blackbacks make it much harder to use these amps this way. The only time I’d ever jump channels is if I wanted a clean pedal platform….. and who buys a classic Marshall for that !!

14:22 one of my favorite Blackmore riffs 🤘🏼