I have opened up ~50 or so Tweed amps from the early 50’s to 1960(even a couple 60 to 63 Champs). I have seen factory substitutions and parallel resistors but not a single audio/log pot. Whoever built this amp did a fine job. It looked a million times better than my first( or 2nd, 3rd…etc).
Congrats Lyle! If you haven't heard yet, you got a very respectable mention tonight on Phillip McKnight's "Know Your Gear" Friday live stream with close to 1,000 people watching. Phil had some really nice things to say about you and your channel. He mentioned you along with two other channels in what he described as sorta of a "pass it along" thing after describing how an established channel mentioned him back when Phil was first getting started.
I have this exact amp built from Mojo's kit - I knew those volume pots were suspicious! Heard "no it's supposed to be that way" but apparently not. Going to change them for the 1Meg linear pots, most excellent tip Lyle. Thanks so much for the video!
You are the man! My brother built this me kit a few years ago, trying to get something like my actual 54 twin,,, and it is LOW OUTPUT. Now we have a small repair to make, thanks so much...
Lyle, I really enjoy your build evaluations. Whether its Suhr or a custom build, you always add context to design that books can’t reveal like a 30 year tech can. Happy Thanksgiving weekend to you and the Psionic family.
Great video! Thanks for evaluating a home kit build. This is the kind of thing that be real useful for fledgling builders (like me). Also, that's a nice clean looking wiring job.
Great evaluation. Who'd have guessed the taper could make such a difference? Proper grounding takes patience and work and wiring dress can almost always be improved. Thanks for sharing.
Lyle - thanks so much for this video and truly honest opinion of the kit and instructions. I know it may not be easy as a Mojo Tone dealer, but kudos for you for your unflappable integrity!
Been waiting for you to do this video! As a DIY builder and repair guy I use your videos as standard settings! If the builder of this amp built the cabinet and applied the tweed my hats off to them for that!
Bravo for catching the audio taper pot error! Many years ago on the old Fender Forum one of the contributors , a vintage tweed collector, mentioned that his original 50s amps had linear taper pots for the volume and I think maybe treble & presence. I’d have to go back and look at my notes. I had the customer’s issue with a 5F4 I’d built, and changing to linear pots made all the difference. When I built my 5E8-A ten years ago I used them and the amp performs great. On Fenders reissue Twin they show linear taper as well on the schematic. On Mojotone’s original kits for this amp they spec’d the same power transformer as for their high power Twin. Sometime in the last ten years they changed the spec to the tweed Bassman PT. Reports came out on the forums that the latter struggled to power the dual rectifier tubes adequately. Something to watch for.
I know it's probably not in your best interest but I would love to see you do a walkthrough of how to make this better. I'm thinking of buying it or one of the other mojotone kits.
Raw tweed will pick up stains easily and fray and fuzz! Pull everything out and either shellac the cab or hit it with some satin poly to seal it up. Fender used to spray them with shellac or nitro celluloid. At least as far as I know!
I have been a working musician for over forty years and around ten years ago I started doing guitar builds and loved it. So I do understand the need (and the fun) to build an amp yourself...it just seems to me that there is a lot more cost involved than in guitar builds. For instance, the amp I was looking at (to build) was a Mojotone Bassman amp, but the parts altogether were around $1700.00-$1900.00 plus tax, plus shipping...and that is just for the bare min. build. Honestly, you can get a brand new Fender Bassman from MF or GC for $1999.00 plus tax and no shipping fee. Perhaps there are better and cheaper Bassman clone kits out there, I haven't really looked yet. But for me, considering the cost and the hassle of these builds...I will most likely just buy one off the rack (so to speak). Last but not least this amp shown here is not even an accurate reproduction of the original, so why bother?! Just my 2 cents worth. Peace.
I must commend you on your recent amp evaluations. This one in particular was excellent. I build for fun at home and the knowledge you have shared has been truly helpful. But I will admit that at times your criticisms of others work have been a bit vitriolic for my taste. These recent ones have been patient, matter of fact and included significant instruction. I know that teaching isn't really your thing but I just wanted you to know how much I have garnered from these latest videos and chats. Thanks.
Can you show how to measure each stage and calculate the gain to see if it's correct so you can know if the total gain and wattage is is correct that would be a good lesson to go over for a video for this amplifier
5E3 often does best with J taper, but audio should be good. Can be too loud too fast with linear. The circuit of the 5E3 is very different than the 5E8-A.
Some TH-cam guitar player built a Mojotone Tweed Deluxe. He found out that the volume knob of the treble channel acted as a "gain" knob for the normal channel and vice versa. Is that something old tweeds had?
To an extent. They are interactive to a degree but I’d have to see that video to know if he wired the volumes right. PS Marshall 4 holers and Fender 5F6-As and 5F8-As have interactive volumes too.
Thumbs up mate! Still learning about toob amps! Obviously very different to solid state amps - log pots mostly there for volume. The 'mixing' with tube amps means they usually have linear (B taper?) pots you say, & some (Vox) use log though. A little confusing! Are there certain circuit topologies that determines linear or log pots? Can one just look at a circuit & know if linear or log should be used? Thanks in advance bud!
The answer is chapter length. Most volume/gain controls in tube amps are audio taper, but there are exceptions. You have to look at the mixing circuit here as a lot of parallel resistances and see how the whole affects the individual pot for it to make sense. This amp passively mixes four input stages so the loss of gain is quite dramatic.
Not to dismiss Mojotone as a company, but they got me a bunch of wrong resistors and a mismatched input transformer for Europe (Deluxe Reverb)…. Took me a lot of mails and pointing out stuff on the schematics to get the right resistors (by that time I already bought them elsewhere to get on with it). Could not exchange the input transformer, because it was part of a kit…..
I can see this happening to a small company overwhelmed with orders. They just need to slow down and get back to where their QC was before the pandemic.
I’m noticing in your videos where it is visible, you use the “pop-less” guitar chord “backwards”…i.e. with the self-grounding plug connected to the amp, rather than to the guitar. Or do you have a guitar chord with the grounding plug on both ends? (can’t always see the end plugged into the guitar.) I have TOTAL respect for everything you do on this channel, so there must be a reason for this…can you set me straight on this? I have a number of these chords (even some of the earlier Ernie Ball models) and swear by them. Thanks in advance! (Maybe if the plug is on both ends, one doesn’t have to worry about which end is plugged into which…)
Got it...Thanks! BTW, I always enjoy your presentations as well as the subject matter. Just ordered a Mojo Deluxe black face...been a few years (40+) since electronic school, and 14 years since a Champ kit build, but what else is there to do? Cheers!
I have opened up ~50 or so Tweed amps from the early 50’s to 1960(even a couple 60 to 63 Champs). I have seen factory substitutions and parallel resistors but not a single audio/log pot.
Whoever built this amp did a fine job. It looked a million times better than my first( or 2nd, 3rd…etc).
Happy Thanksgiving Lyle and family! Thanks for all you do.
Congrats Lyle! If you haven't heard yet, you got a very respectable mention tonight on Phillip McKnight's "Know Your Gear" Friday live stream with close to 1,000 people watching. Phil had some really nice things to say about you and your channel. He mentioned you along with two other channels in what he described as sorta of a "pass it along" thing after describing how an established channel mentioned him back when Phil was first getting started.
I have this exact amp built from Mojo's kit - I knew those volume pots were suspicious! Heard "no it's supposed to be that way" but apparently not. Going to change them for the 1Meg linear pots, most excellent tip Lyle. Thanks so much for the video!
You are the man! My brother built this me kit a few years ago, trying to get something like my actual 54 twin,,, and it is LOW OUTPUT. Now we have a small repair to make, thanks so much...
Glad to see a kit build because I’ve been exploring making that purchase.
A fantastic video and presentation!
Lyle, I really enjoy your build evaluations. Whether its Suhr or a custom build, you always add context to design that books can’t reveal like a 30 year tech can. Happy Thanksgiving weekend to you and the Psionic family.
Hey Lyle, always enjoy your videos. Keep up the good work bro.
Love this video. Taking note for my own builds.
Great video! Thanks for evaluating a home kit build. This is the kind of thing that be real useful for fledgling builders (like me). Also, that's a nice clean looking wiring job.
Great evaluation. Who'd have guessed the taper could make such a difference? Proper grounding takes patience and work and wiring dress can almost always be improved. Thanks for sharing.
Lyle - thanks so much for this video and truly honest opinion of the kit and instructions. I know it may not be easy as a Mojo Tone dealer, but kudos for you for your unflappable integrity!
This was really great! I like this type of review.
Been waiting for you to do this video! As a DIY builder and repair guy I use your videos as standard settings!
If the builder of this amp built the cabinet and applied the tweed my hats off to them for that!
Great advice like this is invaluable...!!!😃
Lyle...You ROCK...!!!
😎👍❤🖖
Bravo for catching the audio taper pot error! Many years ago on the old Fender Forum one of the contributors , a vintage tweed collector, mentioned that his original 50s amps had linear taper pots for the volume and I think maybe treble & presence. I’d have to go back and look at my notes. I had the customer’s issue with a 5F4 I’d built, and changing to linear pots made all the difference. When I built my 5E8-A ten years ago I used them and the amp performs great. On Fenders reissue Twin they show linear taper as well on the schematic. On Mojotone’s original kits for this amp they spec’d the same power transformer as for their high power Twin. Sometime in the last ten years they changed the spec to the tweed Bassman PT. Reports came out on the forums that the latter struggled to power the dual rectifier tubes adequately. Something to watch for.
Good catch on the pot taper, Lyle!
I know it's probably not in your best interest but I would love to see you do a walkthrough of how to make this better. I'm thinking of buying it or one of the other mojotone kits.
Phil McKnight just suggested your channel on his weekly live show. Should bode well for viewership.
Very interesting video.
Thanks for another informative video Lyle. Are you still planning on taking a look at the Marshall Studio Vintage in terms of its build quality etc?
Hope you decide to do something on biasing at some point 🙂
Raw tweed will pick up stains easily and fray and fuzz! Pull everything out and either shellac the cab or hit it with some satin poly to seal it up. Fender used to spray them with shellac or nitro celluloid. At least as far as I know!
I have been a working musician for over forty years and around ten years ago I started doing guitar builds and loved it.
So I do understand the need (and the fun) to build an amp yourself...it just seems to me that there is a lot more cost involved than in guitar builds.
For instance, the amp I was looking at (to build) was a Mojotone Bassman amp, but the parts altogether were around $1700.00-$1900.00 plus tax, plus shipping...and that is just for the bare min. build. Honestly, you can get a brand new Fender Bassman from MF or GC for $1999.00 plus tax and no shipping fee.
Perhaps there are better and cheaper Bassman clone kits out there, I haven't really looked yet. But for me, considering the cost and the hassle of these builds...I will most likely just buy one off the rack (so to speak).
Last but not least this amp shown here is not even an accurate reproduction of the original, so why bother?!
Just my 2 cents worth. Peace.
On second viewing I have to agree with the builder’s speaker choice I really like the Webers myself.
I must commend you on your recent amp evaluations. This one in particular was excellent. I build for fun at home and the knowledge you have shared has been truly helpful. But I will admit that at times your criticisms of others work have been a bit vitriolic for my taste. These recent ones have been patient, matter of fact and included significant instruction. I know that teaching isn't really your thing but I just wanted you to know how much I have garnered from these latest videos and chats. Thanks.
Can you show how to measure each stage and calculate the gain to see if it's correct so you can know if the total gain and wattage is is correct that would be a good lesson to go over for a video for this amplifier
Hey Lyle, just wondering what is that Dohickey "Pointer" that you use?
It's been on my mind everytime I watch a video haha.
Here in the UK CTS linear taper pots are pretty much impossible to find, so maybe supply issues causing substitutions in the kits ?
I don’t think so. Their schematic shows 1MA. The original Fender schematic just says 1M. You kind of have to just know.
Love the content !!
I am now wondering if my upcoming 5e3 build should have linear pots? I ordered 1meg alpha 20% audio
5E3 often does best with J taper, but audio should be good. Can be too loud too fast with linear.
The circuit of the 5E3 is very different than the 5E8-A.
@@PsionicAudio Hi Lyle! Gosh, what is a 'J' taper?
Ok perfect . Thanks very much
Thanks for this tip! I have a lot of trouble controlling the volume on mine. Large spike from 0-1!
30% taper.
What do you charge to mod a new matchless so it doesn’t melt the faceplate? Thx
Great video. I am thinking of getting the Mojotone 5E3. Do you know if it has the same problem with the volume pots?
I can’t say as I haven’t had one. Audio taper volumes are fine in a 5E3 though.
@@PsionicAudio thank you very much for your time
Lyle, I have a question: the vox ac15c1 uses audio taper pots for both preamp volumes and the master volume. What are your thoughts on this?
That is correct for that model.
@@PsionicAudio Yes, but is it a good design?
Going to start a pedal build then a Fender Deluxe build, can you recommend a soldering station? I want to buy once...if I can. ;)
Hakko FX888D about $110.
holy shit , I didnt realize you were just 180 miles away bro... I stay covered up with this stuff
Any problem with a 10w or 5w rheostat in place of resistor for adjustable bias in this? Other than potential for catastrophic user error?
Not necessary. A 1/2W pot suffices.
Some TH-cam guitar player built a Mojotone Tweed Deluxe. He found out that the volume knob of the treble channel acted as a "gain" knob for the normal channel and vice versa. Is that something old tweeds had?
To an extent. They are interactive to a degree but I’d have to see that video to know if he wired the volumes right.
PS Marshall 4 holers and Fender 5F6-As and 5F8-As have interactive volumes too.
Thumbs up mate! Still learning about toob amps! Obviously very different to solid state amps - log pots mostly there for volume. The 'mixing' with tube amps means they usually have linear (B taper?) pots you say, & some (Vox) use log though. A little confusing! Are there certain circuit topologies that determines linear or log pots? Can one just look at a circuit & know if linear or log should be used? Thanks in advance bud!
The answer is chapter length. Most volume/gain controls in tube amps are audio taper, but there are exceptions. You have to look at the mixing circuit here as a lot of parallel resistances and see how the whole affects the individual pot for it to make sense. This amp passively mixes four input stages so the loss of gain is quite dramatic.
So if I understand you correctly. It should be wired: hot is from wall to fuse to switch to primary and neutral directly to other primary. Correct?
Yes. In the US with 120VAC mains.
@@PsionicAudio thank you 😊
Anyone know if mojotone has fixed the low output yet ? - im thinking about getting one.
It’s just the two audio taper volumes. Use linear instead and be happy. Note this advice is specific to this model.
Not to dismiss Mojotone as a company, but they got me a bunch of wrong resistors and a mismatched input transformer for Europe (Deluxe Reverb)…. Took me a lot of mails and pointing out stuff on the schematics to get the right resistors (by that time I already bought them elsewhere to get on with it). Could not exchange the input transformer, because it was part of a kit…..
I can see this happening to a small company overwhelmed with orders. They just need to slow down and get back to where their QC was before the pandemic.
I’m noticing in your videos where it is visible, you use the “pop-less” guitar chord “backwards”…i.e. with the self-grounding plug connected to the amp, rather than to the guitar. Or do you have a guitar chord with the grounding plug on both ends? (can’t always see the end plugged into the guitar.) I have TOTAL respect for everything you do on this channel, so there must be a reason for this…can you set me straight on this? I have a number of these chords (even some of the earlier Ernie Ball models) and swear by them. Thanks in advance! (Maybe if the plug is on both ends, one doesn’t have to worry about which end is plugged into which…)
I have straight on one end and right angle on the other, depending on the guitar.
Got it...Thanks! BTW, I always enjoy your presentations as well as the subject matter. Just ordered a Mojo Deluxe black face...been a few years (40+) since electronic school, and 14 years since a Champ kit build, but what else is there to do? Cheers!
My first bet (before watching) is builder fault. Because it’s happened to me before 😅
Fender and boutique amps ,,occasinal real marshall or carvin ,,peavey always crate