Dude your channel is fiyah! You’re working on all my amps! First the ‘68 SFSR and I also have a ‘74 Superlead I affectionately call “The Howizter”. I’ve recently been thinking about trying different bright caps and here you are again! Thx!
Really awesome to hear the level matched MV samples. Bright caps too. I like 500pf and 1000pf but I find that with a pre-PI MV it makes the amp sound cheap at low volumes. I think I’ll try 4700 again though, after seeing this vid. I also opted for 100pf on my normal channel on my 1987 for the sake of versatility, but there’s also something that gets lost when blending it in. I think it’s super fun to experiment with these simple things, especially since it’s so subjective what you favour and the range of choices is so big!
Thank you YG! Clean work, excellent progress. I thought about putting a post pi lar mar in my 2204 but after learning about the effects on NFB and presence i've held off. I bought a JMP 2204 clone from a guy who had it built and only had it a month for half the money he had in it. I tried it and it sounded like the normal channel of a 4 holer. After a few weeks of checking every component (all good) I was twiddling knobs and noticed presence did nothing til 8 on the pot. I checked the NFB circuit and there it was. Connected to the 8ohm tap. I switched it to the 4ohm tap (per schem with 100k NFB resistor) and BAM! instant brite gainy spanky Marshall goodness. Really opened my eyes to how the NFB circuit affects the overall end result of the tone.
Im loving every video on this bad boy Marshall build, you have to give us a few songs with it at the live gig! I was just trying to figure out which treble bleed values would be best to put on a 3 way switch for my JMP 100 build..Perfect timing for this video!! Thanks for that, really great comparison. I also really liked that 100pf on the normal channel too, it just adds a little bit of clarity while keeping the channel nice and fat.
Right on, and that's the hope! Nearly done with the cab now, finally so she's close! If it were me and I could have 3 options, I'd go no cap, 100pF, and 4.7k/5k pF 🙂
When you complete the project, I recommend the JHS Clover pre-amp pedal. I heard a demo of a JMP with that pedal, the best vintage Marshall sound I have ever heard.
I built an amp which has several gain stages and every stage has a gain pot + bright cap switch with several bright cap options to choose. It is amazing that if you just change the speaker, every speaker and guitar seems to need different bright cap values to get optimal sound. 😅
@@YeatzeeGuitar In fact every stage had switchable plate and cathode resistor and coupling cap values as well, which oddly enough, did not make so much difference. It had three separate switchable tone controls too, (Fender tone stack, passive Baxandall, one pot treble/bass), switchable negative feedback loop, switchable OT snubbers, etc. And of course, it had both pre and post PI master volumes with switchable bright caps. Control freak's amp. 🤓
@@YeatzeeGuitar Both front and back panel are full of switches and pots, I have not counted the number. It has a bypassable Dumble ODS gain stage as well, including it's input trim pot. And triode/pentode switch. It has of course cathode current measurement points to output tubes too. I am planning to install plate and heater voltage meters too, and a small buil-in Variac. Of course, separate heater transformer, so two variacs, would be optimal solution. 🤓
You might want to compare your voltages to some old Marshall charts. Jason at Headfirst has some great videos on how phase inverter node voltages sweeten the amp up. He likes to keep the inverter supply around 330. Sounds great. I liked the 4700 pf cap.
@@scottwilcox6313 because of the replaced PT with a later dagnall it runs lower voltages than you'd expect for the era. I don't recall what it runs at the PI but the plates are around 440
the oddities in your pv are related to the differences in current draw at your power tubes. any future amps i build will have bias adj for each output tube.
I took 2 channels of my Marshall super PA and did the 1-wire mod. Also added a ppi mv. It sounds good but I still prefer my jmp 2203. I think using the right dirt pedal is my preference now. I have heard some awesome sounding modded Marshalls but with mine I usually migrate back to stock configuration. It’s all a personal preference. Mileage may vary.
I read about an easy trick to lessen the effect of the bright cap. A 220k resistor in series with the bright cap to a bit more usable range on the volume knob. Im going to try it on my 50 watt
The more I use them, the more impressed I get. I mean you hear in the comparison here, the amp cranked with master out circuit vs master on 3 or so is pretty dang close when levels are matched. The hard part with MV's, always, is not necessarily the tone itself changing but rather what we hear changing due to the drop in volume.
@YeatzeeGuitar yeah it's hard to beat high volume. I usually don't get a chance to crank it inless the neighbors are out.. I put a lar-mar on nearly every amp I build. Some amps I'll put a pre master and a post. Seems like a never ending quest for good tone at low vol haha
look at rob robinettes cascade mod for the 4 input 5e3 deluxe. it puts v1a & v1b into series as opposed to parallel. that might be worth it to you. i did it in my 5f6-a. not invasive, easily removed.. nice work mate!
@@MichaelSmith-rn1qw no the bias is kept stable, it's just lowering the signal to each of the power tubes. All the gain is from the preamp tubes (PI being a big contributer hence the post PI aspect)
@@YeatzeeGuitar OK, thanks. I have a couple of amps with a master volume (Super Twin Reverb -1976, and Sovtek Tube Midget-1980's), but I don't know how it's implemented. I have schematics for both, I guess I could study them, but the Super Twin Reverb is really complicated, and it's been modified from 180Watts to 120/60Watts.
@@YeatzeeGuitarAnd this was, as you said, pretty straightforward. But I just recently installed a PPI master volume to an amp which has bias balance trimpots, so both output tubes have independent bias voltages. So in that situation you have to use extra caps to isolate grid bias voltages from the dual master volume pot wipers. P.S. A very nice video, especially that bright cap comparison. 👍
I thought the bright cap was across the input jack on a Superlead and would never put a master volume on a Marshall Super. Those people are looking for a different amp. There are plenty of manufacturers that would suit you for that nowadays. Doesn't it sound like removal of the capacitor made a huge difference in gain? For example Superbass vs. Superlead.
? Bright cap across the input jack? Master volume hole already existed in the amp from 1973. As the demo show's, it's highly impressive how little the tone changes going from out of circuit to brought down significantly. There's nothing wrong with trying to make this amp more usable in todays world. I gig in a loud band, I play a vintage AC30 pretty cranked. This amp would not be usable without the MV or an attenuator for me.
Every time I say I do not want to lose time commenting and every time you “provoke” to do so lol 😊 Like I have said filter caps on old pre 1975 Marshall 100 Watt Plexies and 100 Watt Hiwatts are most of the times just fine and last for ever. It comes from using two double 50 uF cans rated at 500V in parallel plus series connection achieving what’s effectively 50 uF 1000V cap. Within working amplifier B+ never reaches even 500V but with no tubes and in some other situations with no load B+ would over volt single 500 V cap. But having 1000V cap makes it last what looks like for ever. Rest of the caps are behind voltage droppers hence those are anyways not exposed to rated voltage. Despite the fact that the power station is brilliant unit I would never use it with 100 Watt amplifier. I would use something that doesn’t reamps the signal. Why wasting 8 power tubes? You are loading amplifier tubes hard to get lower volume and them use 4 more tubes to hear your amplifier. I would rather use the Power Station with small amplifier and big cabinet to get that character of the small amplifier but at the levels usable in the band environment. Actually if the 100 Watt Plexi is to loud bring smaller amplifier. Regarding bright cap and people hating it. Why people bother getting Super Lead and then changing it to something that it is not? The bright cap is part of its gain structure and tradition. Do not like it get Super Bass. Do not like That still get the amplifier that you do like. I use 3 values only. Stock 500 or 470 pF as original. 1000 pF as original to some other Marshall’s when you want more middle part boosted to sound more like some other models. And I use 120 pF if I need just nice top end added. 120 pF and not 100 more because the fact that I have them in-house most often as they are used in Fender amplifiers. I kinda hate disk caps so most often I use Silver Mica caps for pF values. Though they can sound pretty harsh in some circuits. Yet another issue I have is people asking to modify nice original plexies. Especially when it involves drilling chassis. Asking for effect loops and master volumes. I would rather remove one jack to install MV pot in it than drill a hole and ruin chassis originality for ever. Between pre and post MV it is the taste thing. Post does things more transparent, for the lack of the better word, and as expected by players but it is way more intrusive. To be honest if you have need for MV you are having the wrong amplifier. Actually nowadays almost no one needs 100 Watt Plexi because they can’t use it anywhere. Get 18 or 20 Watt Marshall and be done with it. Or if you do use it in band and loud drummer is an issue get up to 50 Watt model maximum. You worry about originality of the bridge wire color and at same time install PPI MV? 😊 To each it’s own I guess. Keeping up appearances. Even if your power transformer was changed it was changed with original replacement and that doesn’t take away from its originality and does not bother me. If I do not have original wire used and I have to use something else it doesn’t bother me to use other color wire. I am functioning in two manners. One being originality and the second making things functional and bulletproof. Both ways are fine by me. Still when I see amplifier that’s as good as original I am leaning towards originality always. Considering how many butchered Marshall’s I have seen yours is and even was very good example. I think that it is more probable to find all original old Marshall in the USA than in the Europe. In the USA they were something special and people took care of them and respected them more. Here they were plentiful and cheap in 90’s as they were just old amplifiers people modified how they wanted. In 90’s heavy metals phase people traded them in to get JCM800 and traded them for cheap too. In return they got PCB amplifier. GG. Personally I would keep it stock. Use it just when there is a need for a weapon or scaring modern “all I need is interface” players by letting them play full stack. For everything else I would use my amplifiers anyways. If I need that Plexi sound on lower level I would use my variation of the Bluesbreaker 18 Watt. Bringing full stack and running it choked up is just posing for me.
😂 Sorry! Lol. Can't say I agree with everything, but lots of valid points. I play in a loud band that plays the loudest rooms in our area, and even still there's no where this amp could be played at the volume it requires to have good tone and not sound shrill. The amp obviously already had the hole for the MV so ppimv wasn't a bit deal, and hugely impressive to me how well it works on its own. The fryette works great as well, critically it's main advantage is that it's got footswitchable fx loop and 2 "presets". For live use both are invaluable
@YeatzeeGuitar like I have saud to each it's own. Everyone has its needs and preferences, and that's good. I madly respect Fryette. He knows his shit. I would never burn two sets of tubes, though. I would use a simple load box at most and rather use nothing because there is nothing like Suoer Lead 100 into a full stack without any limitations. Loud band is great and fir that you need good amplifier. Though I am not rating power needed by band. I rate it by the venues where you are playing. It makes 0 sense to je playing this in 50 man bar with a small stage. While playing stadiums and huge venues, I am still fie wall of full stacks.
i've seen vids of bright cap swaps before but never with as much distinction as im hearing here. good grief. is it as proinent live as it is thru yt treatments?.
It's very dramatic in person. I figured a middle of the road value like the 750pF could be cool, I didn't realize just how much more mids / girth comes in with the super high value caps and those mid value ones just sound nasty. All top, no meat. The big caps are gnarly sound in person as well, they really come into their own when the amp is unbelievably deafeningly loud (without the master)
12:05 - Bright Cap Comparison!
21:35 - Master volume install
31:03 - Master Volume Audio Test
Dude your channel is fiyah! You’re working on all my amps! First the ‘68 SFSR and I also have a ‘74 Superlead I affectionately call “The Howizter”. I’ve recently been thinking about trying different bright caps and here you are again! Thx!
@@kevinafflack 🤘🤘🤘
Imagine the crowd sound levels these were built to overcome!
Definitely post some shorts from your future Wembley shows! 😊😮😊
I'm editing up some clips from the recent show with it right now! Hopefully have it done by Thursday 👍
Really awesome to hear the level matched MV samples. Bright caps too. I like 500pf and 1000pf but I find that with a pre-PI MV it makes the amp sound cheap at low volumes. I think I’ll try 4700 again though, after seeing this vid.
I also opted for 100pf on my normal channel on my 1987 for the sake of versatility, but there’s also something that gets lost when blending it in.
I think it’s super fun to experiment with these simple things, especially since it’s so subjective what you favour and the range of choices is so big!
Thank you YG! Clean work, excellent progress.
I thought about putting a post pi lar mar in my 2204 but after learning about the effects on NFB and presence i've held off.
I bought a JMP 2204 clone from a guy who had it built and only had it a month for half the money he had in it. I tried it and it sounded like the normal channel of a 4 holer. After a few weeks of checking every component (all good) I was twiddling knobs and noticed presence did nothing til 8 on the pot. I checked the NFB circuit and there it was. Connected to the 8ohm tap.
I switched it to the 4ohm tap (per schem with 100k NFB resistor) and BAM! instant brite gainy spanky Marshall goodness.
Really opened my eyes to how the NFB circuit affects the overall end result of the tone.
Im loving every video on this bad boy Marshall build, you have to give us a few songs with it at the live gig!
I was just trying to figure out which treble bleed values would be best to put on a 3 way switch for my JMP 100 build..Perfect timing for this video!! Thanks for that, really great comparison. I also really liked that 100pf on the normal channel too, it just adds a little bit of clarity while keeping the channel nice and fat.
Right on, and that's the hope! Nearly done with the cab now, finally so she's close!
If it were me and I could have 3 options, I'd go no cap, 100pF, and 4.7k/5k pF 🙂
@@YeatzeeGuitar Awesome, might start with those values then!
When you complete the project, I recommend the JHS Clover pre-amp pedal. I heard a demo of a JMP with that pedal, the best vintage Marshall sound I have ever heard.
I had a 1959 Plexi. I used a Scholz power soak for the master volume.😂
Superb work as usual
🙏🙏
I built an amp which has several gain stages and every stage has a gain pot + bright cap switch with several bright cap options to choose. It is amazing that if you just change the speaker, every speaker and guitar seems to need different bright cap values to get optimal sound. 😅
Wow!
@@YeatzeeGuitar In fact every stage had switchable plate and cathode resistor and coupling cap values as well, which oddly enough, did not make so much difference. It had three separate switchable tone controls too, (Fender tone stack, passive Baxandall, one pot treble/bass), switchable negative feedback loop, switchable OT snubbers, etc. And of course, it had both pre and post PI master volumes with switchable bright caps. Control freak's amp. 🤓
How many switches total? Sounds like it lol
@@YeatzeeGuitar Both front and back panel are full of switches and pots, I have not counted the number. It has a bypassable Dumble ODS gain stage as well, including it's input trim pot. And triode/pentode switch. It has of course cathode current measurement points to output tubes too. I am planning to install plate and heater voltage meters too, and a small buil-in Variac. Of course, separate heater transformer, so two variacs, would be optimal solution. 🤓
Thanks for the video.
You might want to compare your voltages to some old Marshall charts. Jason at Headfirst has some great videos on how phase inverter node voltages sweeten the amp up. He likes to keep the inverter supply around 330. Sounds great. I liked the 4700 pf cap.
@@scottwilcox6313 because of the replaced PT with a later dagnall it runs lower voltages than you'd expect for the era. I don't recall what it runs at the PI but the plates are around 440
the oddities in your pv are related to the differences in current draw at your power tubes.
any future amps i build will have bias adj for each output tube.
I took 2 channels of my Marshall super PA and did the 1-wire mod. Also added a ppi mv. It sounds good but I still prefer my jmp 2203. I think using the right dirt pedal is my preference now. I have heard some awesome sounding modded Marshalls but with mine I usually migrate back to stock configuration. It’s all a personal preference. Mileage may vary.
I still really want to try a jmp 2203
I read about an easy trick to lessen the effect of the bright cap. A 220k resistor in series with the bright cap to a bit more usable range on the volume knob. Im going to try it on my 50 watt
Heard about that, maybe I'll try it sometime
Nice install on rhe lar-mar. Looks better than flying up over the board. Its my favorite mv even though you seem to lose nfb and presence.
The more I use them, the more impressed I get. I mean you hear in the comparison here, the amp cranked with master out circuit vs master on 3 or so is pretty dang close when levels are matched. The hard part with MV's, always, is not necessarily the tone itself changing but rather what we hear changing due to the drop in volume.
@YeatzeeGuitar yeah it's hard to beat high volume. I usually don't get a chance to crank it inless the neighbors are out.. I put a lar-mar on nearly every amp I build. Some amps I'll put a pre master and a post. Seems like a never ending quest for good tone at low vol haha
look at rob robinettes cascade mod for the 4 input 5e3 deluxe. it puts v1a & v1b into series as opposed to parallel. that might be worth it to you. i did it in my 5f6-a. not invasive, easily removed.. nice work mate!
So what is that master volume pot actually doing? Increasing the negative voltage to the grids as you turn it down?
@@MichaelSmith-rn1qw no the bias is kept stable, it's just lowering the signal to each of the power tubes. All the gain is from the preamp tubes (PI being a big contributer hence the post PI aspect)
@@YeatzeeGuitar OK, thanks. I have a couple of amps with a master volume (Super Twin Reverb -1976, and Sovtek Tube Midget-1980's), but I don't know how it's implemented. I have schematics for both, I guess I could study them, but the Super Twin Reverb is really complicated, and it's been modified from 180Watts to 120/60Watts.
@@YeatzeeGuitarAnd this was, as you said, pretty straightforward. But I just recently installed a PPI master volume to an amp which has bias balance trimpots, so both output tubes have independent bias voltages. So in that situation you have to use extra caps to isolate grid bias voltages from the dual master volume pot wipers.
P.S. A very nice video, especially that bright cap comparison. 👍
I thought the bright cap was across the input jack on a Superlead and would never put a master volume on a Marshall Super. Those people are looking for a different amp. There are plenty of manufacturers that would suit you for that nowadays. Doesn't it sound like removal of the capacitor made a huge difference in gain? For example Superbass vs. Superlead.
? Bright cap across the input jack? Master volume hole already existed in the amp from 1973. As the demo show's, it's highly impressive how little the tone changes going from out of circuit to brought down significantly. There's nothing wrong with trying to make this amp more usable in todays world. I gig in a loud band, I play a vintage AC30 pretty cranked. This amp would not be usable without the MV or an attenuator for me.
Shockingly loud!!!
Hahahaha!
I played a mates 50w thru a 4x10 in anger..
This thing wd belt the wax out ur ears!
Every time I say I do not want to lose time commenting and every time you “provoke” to do so lol 😊
Like I have said filter caps on old pre 1975 Marshall 100 Watt Plexies and 100 Watt Hiwatts are most of the times just fine and last for ever. It comes from using two double 50 uF cans rated at 500V in parallel plus series connection achieving what’s effectively 50 uF 1000V cap. Within working amplifier B+ never reaches even 500V but with no tubes and in some other situations with no load B+ would over volt single 500 V cap. But having 1000V cap makes it last what looks like for ever. Rest of the caps are behind voltage droppers hence those are anyways not exposed to rated voltage.
Despite the fact that the power station is brilliant unit I would never use it with 100 Watt amplifier. I would use something that doesn’t reamps the signal. Why wasting 8 power tubes? You are loading amplifier tubes hard to get lower volume and them use 4 more tubes to hear your amplifier. I would rather use the Power Station with small amplifier and big cabinet to get that character of the small amplifier but at the levels usable in the band environment.
Actually if the 100 Watt Plexi is to loud bring smaller amplifier.
Regarding bright cap and people hating it. Why people bother getting Super Lead and then changing it to something that it is not? The bright cap is part of its gain structure and tradition. Do not like it get Super Bass. Do not like That still get the amplifier that you do like.
I use 3 values only. Stock 500 or 470 pF as original. 1000 pF as original to some other Marshall’s when you want more middle part boosted to sound more like some other models. And I use 120 pF if I need just nice top end added. 120 pF and not 100 more because the fact that I have them in-house most often as they are used in Fender amplifiers.
I kinda hate disk caps so most often I use Silver Mica caps for pF values. Though they can sound pretty harsh in some circuits.
Yet another issue I have is people asking to modify nice original plexies. Especially when it involves drilling chassis. Asking for effect loops and master volumes. I would rather remove one jack to install MV pot in it than drill a hole and ruin chassis originality for ever.
Between pre and post MV it is the taste thing. Post does things more transparent, for the lack of the better word, and as expected by players but it is way more intrusive. To be honest if you have need for MV you are having the wrong amplifier. Actually nowadays almost no one needs 100 Watt Plexi because they can’t use it anywhere. Get 18 or 20 Watt Marshall and be done with it. Or if you do use it in band and loud drummer is an issue get up to 50 Watt model maximum.
You worry about originality of the bridge wire color and at same time install PPI MV? 😊 To each it’s own I guess. Keeping up appearances. Even if your power transformer was changed it was changed with original replacement and that doesn’t take away from its originality and does not bother me. If I do not have original wire used and I have to use something else it doesn’t bother me to use other color wire. I am functioning in two manners. One being originality and the second making things functional and bulletproof. Both ways are fine by me. Still when I see amplifier that’s as good as original I am leaning towards originality always. Considering how many butchered Marshall’s I have seen yours is and even was very good example. I think that it is more probable to find all original old Marshall in the USA than in the Europe. In the USA they were something special and people took care of them and respected them more. Here they were plentiful and cheap in 90’s as they were just old amplifiers people modified how they wanted. In 90’s heavy metals phase people traded them in to get JCM800 and traded them for cheap too. In return they got PCB amplifier. GG.
Personally I would keep it stock. Use it just when there is a need for a weapon or scaring modern “all I need is interface” players by letting them play full stack. For everything else I would use my amplifiers anyways.
If I need that Plexi sound on lower level I would use my variation of the Bluesbreaker 18 Watt. Bringing full stack and running it choked up is just posing for me.
😂 Sorry! Lol. Can't say I agree with everything, but lots of valid points. I play in a loud band that plays the loudest rooms in our area, and even still there's no where this amp could be played at the volume it requires to have good tone and not sound shrill. The amp obviously already had the hole for the MV so ppimv wasn't a bit deal, and hugely impressive to me how well it works on its own. The fryette works great as well, critically it's main advantage is that it's got footswitchable fx loop and 2 "presets". For live use both are invaluable
@YeatzeeGuitar like I have saud to each it's own. Everyone has its needs and preferences, and that's good. I madly respect Fryette. He knows his shit. I would never burn two sets of tubes, though. I would use a simple load box at most and rather use nothing because there is nothing like Suoer Lead 100 into a full stack without any limitations. Loud band is great and fir that you need good amplifier. Though I am not rating power needed by band. I rate it by the venues where you are playing. It makes 0 sense to je playing this in 50 man bar with a small stage. While playing stadiums and huge venues, I am still fie wall of full stacks.
If you modify tube amps on UA-cam, you just might be a Dumble.
i've seen vids of bright cap swaps before but never with as much distinction as im hearing here. good grief. is it as proinent live as it is thru yt treatments?.
It's very dramatic in person. I figured a middle of the road value like the 750pF could be cool, I didn't realize just how much more mids / girth comes in with the super high value caps and those mid value ones just sound nasty. All top, no meat. The big caps are gnarly sound in person as well, they really come into their own when the amp is unbelievably deafeningly loud (without the master)
@@YeatzeeGuitar yeah & thats predictable. if your able to attenuate & can twist the knobs, the cap may not factor in as much. try jumpering as well.
@@YeatzeeGuitar the volume differences are what knocked me.
Yes, significant gain differences!