Man - you knocked that one out of the park! I’ll bet you reduced the hum by 6-9 dB. I was listening in headphones. You would think, the smaller builders would watch your videos and incorporate the modifications you present. I understand the assembly line Vox/Fender corporations (hate em - but get it). The boutique builders? How foolish. BTW - saw a guy with Vox issues post on Reddit the other day looking for help. As I scrolled down the thread I saw someone say “get in touch with Lyle at Psionic Audio. He knows everything about Vox’s” and left a link. Made me happy to see that
Hi Lyle, can you tell me more about that very nice tech in Germany you mentioned in this video? Because I live in Germany and could need a very nice tech to look at my old Fender amp. Dankeschön! 😃
That's a great tip about the J Taper volume and treble pots. I've never heard or read about that before. Where can I buy J Taper 1 Meg volume pots? Thanks
This is a great video that is very informative. Thank you very much. The band-aid capacitor 10/22uF to be installed in this bias wiper part, what is the rated voltage? If you don't mind, please let me know. I look forward to more videos in the future.
i don't get why people still copy that outdated lousy filtering in some amps, especially champs, but i always glad to hear some words of common sense from you
Great vid! I'm new to your channel and really enjoy watching you go through these. You should consider a series where you look at amp guts shots either in your shop or maybe photos, and rate it. Like hot or not, or rate or roast your amp, something like that anyways. You'd get at least one view ;0) We always see youtubers praise all of these products, and would be great to here your take on if it's a truly great/competent build, boutique or not, and the good, the bad and the ugly, what recommendations you have for easy upgrade etc. If not, oh well, keep it up anyway; great vids!
Thanks, but that's a slippery slope to chasing being a "UA-cam personality" just desperate for clicks. Unless I have it on my bench and can measure it and listen to it, I don't want to offer opinions on amps. I mean, aside from the ego trap, it's kind of pointless. I am just one of hundreds of techs who routinely point out how garbage Mesa amps are, and they remain really popular with players. Sure, fine, whatever. Mesas make us techs a lot of money. Keep on buying the shit and paying us to keep it limping along... ;)
Did anyone see the Tone Talk interview of Morgan Amps? The guy did not even look in the camera, played a game the whole time and seemed a bit off. I can not imagine that he cares for tone or customers. Thanks Lyle, for the lesson and inspiration.
When you get the chance try a diode in line with HT center taps reduces IMD a good bit . Even though bias supply have very lite loads filtering the bias after a full wave diode bridge rather than single diode as you see here maters a great deal.. uf1007 my preffered diodes for bias or her1008s with a good sized cap. Enjoy the video.
@@goodun2974 Depends on the voltage since most are under 600ac voltage uf1007 works for me current under an amp . When in question double them up . My preference is two secondarys with out a center tap . This is more complex and not the way to go on a moble rig. Think of the center tap going negative to ground . If you feel this adds complexity is with out value then do not do it . As with any of these mods weight the cost to return for you. I prefer uf1007 to 1n1007 because of the noise both audio and rf band .
I do think this amp sounds pretty good. I learned alot here. Have you been inside any Divided by 13 amps? If so I'm curious what you thought of the build quality, layout, and if there was anything that should have been better or quieter like you seen in this amp. I'm hoping you get one in the shop and on a video.
Well, I am an expert and I don't like them either. ;) Too easy to overheat the cap when installing. Can shorten cap life and it's an easily avoided mistake.
I have a Morgan MVP 23 combo, cathode biased el84, no reverb or trem, single channel with a voltage regulator. It's not a copy of a particular amp but has a mid control that adds gain past a certain point. Has a volume (output) and a gain (preamp) control that lets you drive the preamp, power section, or any combination of the two along with the power scaling to set overall volume. Doesn't nail the sound of a particular amp but it is super versatile and can get close to a black Fender, can get Voxy, crank the gain and mids and it's very plexi-esque, all with no channel switching. It does everything I want it to beautifully and, my point after all this rambling, it is DEAD QUIET. After watching this, should I worry about the build/component quality or just be glad that it does exactly what I want it to do and enjoy it?
In case anyone was confused at 6:45 when Lyle said "in Germany its 100 Hz, in the US it's 120 [Hz]; and you get partials like 240", or something like that, I think he was describing the frequency of the hum or power supply ripple from a bridge rectifier. (?). The 50 Hz mains supply in Germany generates primarily 50 Hz hum from a fullwave rectifier with capacitor,, but using a bridge rectifier and capacitor gives you 100 Hz ripple, and the higher-frequency ripple is easier to filter (requires less capacitance or fewer filtering nodes,). Ditto for the 60Hz USA mains supply; a full wave rectifier delivers 60 Hz ripple but a bridge rectifier has 120 Hz ripple. Again, the higher frequency ripple is easier to filter out. But, I assume this amp uses full-wave rectifiers as classic Fenders do, and i didn't hear Lyle mention a bridge rectifier circuit, so, I'm still confused ! Lyle can ---- and should! ---- squawk at me if I misunderstood what he was getting at. I haven't watched the entire video yet, I usually pause and comment as it goes along, because otherwise by the time I get to the end I forget what the comment was that I wanted to make, or any underlying question that I might have, and what part of the video I wanted to reference it to! [Edit ---- I listened to what Lyle said again, a bit louder and after having drunk more coffee, about having "partials at 240" ---- I assume he means higher frequency harmonics in the ripple frequency, at 240 hertz].
@@PsionicAudio , I know that, which is why I was confused about your mention of 100 Hz, 120 Hz and 240 VAC; I couldn't quite figure how that was germaine to improving the bias supply if indeed it was a half-wave supply as found, and not being modified/ upgraded. But then, somebody else here mentioned replacing the half wave bias supply with a bridge rectifier, further muddying the waters.....
Well, honestly, I think I troubleshot this in sightly the wrong order. Thinking about it over coffee this morning I think the 120Hz in the bias supply was initially because it was grounded to the same point as the HT CT. After I changed that ground there was still hum but I didn't measure whether it was 120Hz or 60Hz, and through a speaker they can sound the same (at this point I was listening not scoping). Moving the HT CT wire to a new chassis connection got rid of the last bit of hum. I probably could have removed that added 22uf on the bias wiper at that point, but it certainly wasn't hurting anything there and I wanted to stop the clock on the repair at that point once the hum was gone. The amp shipped yesterday, so it's moot now. If Morgan had copied Leo's ground scheme none of this would have been necessary. But this amp had hobbyist mistakes.
@@PsionicAudio I would use a lot higher value of cap for the first in line after the diode 4700mfd . If you get the chance try a full wave bridge on your princeton amp a small resistor then 4700 mfd and a load resistor for say 10ma . See what you think of the sound . Should be quieter. There is a chance you may not like the difference . I would be interested in your results. Regards
Too bad you are too far away. Otherwise would hire you as my amp tech. Whoever knows anything about that can immediately realize that you know your stuff. Great job!
Just goes to show you the majority of boutique builders are merely cloners with zero technical chops. They put amps together mechanically and that’s all.
Your videos are great, thanks for posting!
I have a Carr Mercury V and watched the Carr video you put up.
Another master class in amp design. Thank you.
Great sound Lyle, I was surprised after you told us it wasn't an eyelet board..! I need new glasses. great service & repair..Ed..uk..😁
Hey love that t-shirt, Lyle!
Excellent job Professor 👏
Nice job and tips Buddy.... Thanks Lyle
Man - you knocked that one out of the park! I’ll bet you reduced the hum by 6-9 dB. I was listening in headphones. You would think, the smaller builders would watch your videos and incorporate the modifications you present. I understand the assembly line Vox/Fender corporations (hate em - but get it). The boutique builders? How foolish. BTW - saw a guy with Vox issues post on Reddit the other day looking for help. As I scrolled down the thread I saw someone say “get in touch with Lyle at Psionic Audio. He knows everything about Vox’s” and left a link. Made me happy to see that
I hear things man...things😂 great video 👊😎
Hi Lyle, can you tell me more about that very nice tech in Germany you mentioned in this video? Because I live in Germany and could need a very nice tech to look at my old Fender amp. Dankeschön! 😃
That's a great tip about the J Taper volume and treble pots. I've never heard or read about that before.
Where can I buy J Taper 1 Meg volume pots?
Thanks
Tubesandmore.com
Heyo Lyle... If I were/was Joe Morgan, I'd thank you very much and incorporate your mods in future PR clones
This is a great video that is very informative. Thank you very much.
The band-aid capacitor 10/22uF to be installed in this bias wiper part, what is the rated voltage? If you don't mind, please let me know.
I look forward to more videos in the future.
Thanks. I used a 63v but would have preferred a 100v to have more margin. The supply wasn’t going to exceed 50v but still.
i don't get why people still copy that outdated lousy filtering in some amps, especially champs, but i always glad to hear some words of common sense from you
Great vid! I'm new to your channel and really enjoy watching you go through these. You should consider a series where you look at amp guts shots either in your shop or maybe photos, and rate it. Like hot or not, or rate or roast your amp, something like that anyways. You'd get at least one view ;0) We always see youtubers praise all of these products, and would be great to here your take on if it's a truly great/competent build, boutique or not, and the good, the bad and the ugly, what recommendations you have for easy upgrade etc. If not, oh well, keep it up anyway; great vids!
Thanks, but that's a slippery slope to chasing being a "UA-cam personality" just desperate for clicks.
Unless I have it on my bench and can measure it and listen to it, I don't want to offer opinions on amps.
I mean, aside from the ego trap, it's kind of pointless. I am just one of hundreds of techs who routinely point out how garbage Mesa amps are, and they remain really popular with players. Sure, fine, whatever. Mesas make us techs a lot of money. Keep on buying the shit and paying us to keep it limping along... ;)
Did anyone see the Tone Talk interview of Morgan Amps? The guy did not even look in the camera, played a game the whole time and seemed a bit off. I can not imagine that he cares for tone or customers. Thanks Lyle, for the lesson and inspiration.
I never actually thought about what color ground wire to use in an ac/dc circute
When you get the chance try a diode in line with HT center taps reduces IMD a good bit . Even though bias supply have very lite loads filtering the bias after a full wave diode bridge rather than single diode as you see here maters a great deal.. uf1007 my preffered diodes for bias or her1008s with a good sized cap. Enjoy the video.
IMD; intermodulation distortion?
@@goodun2974 Correct.
@@johnwilliamson467 how big a diode would you use in line with the H-T centertap ( to ground)? Something spec'd higher than a 1n4007 I presume!
@@goodun2974 Depends on the voltage since most are under 600ac voltage uf1007 works for me current under an amp . When in question double them up . My preference is two secondarys with out a center tap . This is more complex and not the way to go on a moble rig. Think of the center tap going negative to ground . If you feel this adds complexity is with out value then do not do it . As with any of these mods weight the cost to return for you. I prefer uf1007 to 1n1007 because of the noise both audio and rf band .
I do think this amp sounds pretty good. I learned alot here. Have you been inside any Divided by 13 amps? If so I'm curious what you thought of the build quality, layout, and if there was anything that should have been better or quieter like you seen in this amp. I'm hoping you get one in the shop and on a video.
facebook.com/PsionicAudio/videos/363293861025861/?sfnsn=mo
@@PsionicAudio Oh hey thanks. I must have missed that one.
Im no expert but I dont like those connections with a resistor wound around a cap?
Well, I am an expert and I don't like them either. ;)
Too easy to overheat the cap when installing. Can shorten cap life and it's an easily avoided mistake.
I have a Morgan MVP 23 combo, cathode biased el84, no reverb or trem, single channel with a voltage regulator. It's not a copy of a particular amp but has a mid control that adds gain past a certain point. Has a volume (output) and a gain (preamp) control that lets you drive the preamp, power section, or any combination of the two along with the power scaling to set overall volume. Doesn't nail the sound of a particular amp but it is super versatile and can get close to a black Fender, can get Voxy, crank the gain and mids and it's very plexi-esque, all with no channel switching. It does everything I want it to beautifully and, my point after all this rambling, it is DEAD QUIET. After watching this, should I worry about the build/component quality or just be glad that it does exactly what I want it to do and enjoy it?
If you love it and it's been reliable for you, fantastic. I have no experience with that model, so I have no opinion of it.
@@PsionicAudio that it has, not a hiccup. Thank you for the reply!
perhaps i'm crazy... but that looks like a cool amp.
It sounds a lot cooler now without the hum.
In case anyone was confused at 6:45 when Lyle said "in Germany its 100 Hz, in the US it's 120 [Hz]; and you get partials like 240", or something like that, I think he was describing the frequency of the hum or power supply ripple from a bridge rectifier. (?). The 50 Hz mains supply in Germany generates primarily 50 Hz hum from a fullwave rectifier with capacitor,, but using a bridge rectifier and capacitor gives you 100 Hz ripple, and the higher-frequency ripple is easier to filter (requires less capacitance or fewer filtering nodes,). Ditto for the 60Hz USA mains supply; a full wave rectifier delivers 60 Hz ripple but a bridge rectifier has 120 Hz ripple. Again, the higher frequency ripple is easier to filter out. But, I assume this amp uses full-wave rectifiers as classic Fenders do, and i didn't hear Lyle mention a bridge rectifier circuit, so, I'm still confused ! Lyle can ---- and should! ---- squawk at me if I misunderstood what he was getting at. I haven't watched the entire video yet, I usually pause and comment as it goes along, because otherwise by the time I get to the end I forget what the comment was that I wanted to make, or any underlying question that I might have, and what part of the video I wanted to reference it to! [Edit ---- I listened to what Lyle said again, a bit louder and after having drunk more coffee, about having "partials at 240" ---- I assume he means higher frequency harmonics in the ripple frequency, at 240 hertz].
Bias supply is half wave rectification.
@@PsionicAudio , I know that, which is why I was confused about your mention of 100 Hz, 120 Hz and 240 VAC; I couldn't quite figure how that was germaine to improving the bias supply if indeed it was a half-wave supply as found, and not being modified/ upgraded. But then, somebody else here mentioned replacing the half wave bias supply with a bridge rectifier, further muddying the waters.....
Well, honestly, I think I troubleshot this in sightly the wrong order. Thinking about it over coffee this morning I think the 120Hz in the bias supply was initially because it was grounded to the same point as the HT CT. After I changed that ground there was still hum but I didn't measure whether it was 120Hz or 60Hz, and through a speaker they can sound the same (at this point I was listening not scoping). Moving the HT CT wire to a new chassis connection got rid of the last bit of hum.
I probably could have removed that added 22uf on the bias wiper at that point, but it certainly wasn't hurting anything there and I wanted to stop the clock on the repair at that point once the hum was gone. The amp shipped yesterday, so it's moot now.
If Morgan had copied Leo's ground scheme none of this would have been necessary. But this amp had hobbyist mistakes.
@@PsionicAudio I would use a lot higher value of cap for the first in line after the diode 4700mfd . If you get the chance try a full wave bridge on your princeton amp a small resistor then 4700 mfd and a load resistor for say 10ma . See what you think of the sound . Should be quieter. There is a chance you may not like the difference . I would be interested in your results. Regards
Kudos to you. Stick to your guns. No false adv.
Too bad you are too far away. Otherwise would hire you as my amp tech. Whoever knows anything about that can immediately realize that you know your stuff. Great job!
This amp is a classic example of a builder that doesn't know amps....sorry Morgan lovers.
Just goes to show you the majority of boutique builders are merely cloners with zero technical chops. They put amps together mechanically and that’s all.
Overrated and Overpriced another amp that I won't be buying!