Hey group!
I've received most of the parts I've ordered for my tube amp build. I've watched a number of videos and read articles that discuss the suggested layout of the components but I'd like to hear from anyone with their thoughts of the layout I've setup on the chassis. The PDF file should show some annotations of what's what.
To briefly describe the plan, I'm attempting to make a single-channel amp with lots of headroom in hopes of having a "pedal platform" amp, i.e. very little/no distortion throughout the amp (hence the single preamp). The amp will have an active mix effects loop, reverb tank and 2 6l6GC output tubes. As the attachment shows, I haven't selected an output transformer or placed the 6L6s yet, so there's some work to do there. Also note that I wanted to have a Line Out jack, which would be driven by another 12AX7 but didn't lay that out as I'm not sure of the best place to put it.
I'm planning on using a turret board under the chassis for the component build but can't get past this part so not overly worried about that yet!
The knobs at the front, from Left to right are: Gain, Bass, Mid, Treb, Reverb, Presence and Master. I think I'm going to place the power switch and fuse in the back behind the power transformer. There will also be an IEC cord connector in that area, and then off to the left (as looking at it), there will be the Effects Loop jacks, Line Out jack and the speaker output to the far left behind the output transformer (once I install it).
Again, any thoughts or ideas you'd be willing to share, I'd appreciate hearing them!
Tube Chassis Layout
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Tube Chassis Layout
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Last edited by JJH0906 on Sun Dec 19, 2021 10:18 pm, edited 1 time in total.
Re: Tube Chassis Layout
In order to offer good useful feedback/help, it would have been extremely helpful to have a schematic to look at.
Where are planning to put the phase invertor tube?
I would NOT personally put the output tubes on the same side of the amp as the preamp or reverb tubes. I'd put the output tubes near the OT and PT. And closer to the rectifier.
There are so many good examples of tube amp layouts out there .................... I'd go back and study them some more and look for a pattern of how those are laid out. As a starting place, look at the Fender, Marshall and Dumble examples. I would not use Matchless, HiWatt, Trainwreck or Mesa Boogie as a good starting place for your amp design. And all of those amps are great amps but I wouldn't start with those for a "clean pedal platform" design.
With respect, 10thtx
Where are planning to put the phase invertor tube?
I would NOT personally put the output tubes on the same side of the amp as the preamp or reverb tubes. I'd put the output tubes near the OT and PT. And closer to the rectifier.
There are so many good examples of tube amp layouts out there .................... I'd go back and study them some more and look for a pattern of how those are laid out. As a starting place, look at the Fender, Marshall and Dumble examples. I would not use Matchless, HiWatt, Trainwreck or Mesa Boogie as a good starting place for your amp design. And all of those amps are great amps but I wouldn't start with those for a "clean pedal platform" design.
With respect, 10thtx
Re: Tube Chassis Layout
A clean pedal platform is great, but an FX loop offers no benefit in such an amp.
I build and repair tube amps. http://amps.monkeymatic.com
Re: Tube Chassis Layout
The OT may be labelled ‘line choke’?
4 triode sections dedicated to an fx loop seems an unusual design choice?
Why would a line out require one triode section, nevermind 2?
4 triode sections dedicated to an fx loop seems an unusual design choice?
Why would a line out require one triode section, nevermind 2?
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Re: Tube Chassis Layout
Thanks for some of your thoughts!
As far as the schematic goes, I have it in parts and pieces. I haven't put it all on one sheet or got it all laid out bit by bit yet. Sounds erratic, it's all there, just don't have it all nice and pretty. The circuits are very typical from stuff that's out there, mostly based off Fender models, so there's an idea of what the plan is.
The phase inverter was going to be over by the output tubes and the output transformer but I appreciate you pointing out that should be moved away from the input side of things. I had seen a couple other videos that suggested the same thing so I have to rearrange the components a bit to make that work better.
As far as the schematic goes, I have it in parts and pieces. I haven't put it all on one sheet or got it all laid out bit by bit yet. Sounds erratic, it's all there, just don't have it all nice and pretty. The circuits are very typical from stuff that's out there, mostly based off Fender models, so there's an idea of what the plan is.
The phase inverter was going to be over by the output tubes and the output transformer but I appreciate you pointing out that should be moved away from the input side of things. I had seen a couple other videos that suggested the same thing so I have to rearrange the components a bit to make that work better.
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Stevem
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2 others liked this
Re: Tube Chassis Layout
If this is your first build, then your diving into way too deep water!
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Re: Tube Chassis Layout
Yeah I know. Typical me. In the end I expect to spend about asich as just buying a nice amp. Go figger...
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Stevem
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- Location: 1/3rd the way out one of the arms of the Milkyway.
Re: Tube Chassis Layout
If you go to the Fender amp field guide site you can view the chassis layout for just about every amp they have listed there besides the schematic.
If you follow one of those layouts you should go too far off the rails!
One important change would be to have the phase splitter tube centered with the output tubes to make for the shortest grid wire runs to the output tubes.
Also if the wire run from the input jack can not be made under 3 inches long then be sure to use sheilded wire to get you there.
If you follow one of those layouts you should go too far off the rails!
One important change would be to have the phase splitter tube centered with the output tubes to make for the shortest grid wire runs to the output tubes.
Also if the wire run from the input jack can not be made under 3 inches long then be sure to use sheilded wire to get you there.
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Re: Tube Chassis Layout
There is much more to consider than just the "nice" or "rules of thumb" placement. Read the article of Richard Kuehnel (https://ampbooks.com/mobile/amp-technology/layout/). He took a "forensic approach" to Fender's layout principles, very interesting. Base line: Avoid traps for hum and crosstalk, Layout follows function (or at least things to avoid), stick to proven layouts.
Another great source for layout tips is the Valve Wizard .
I always follow their rules and never failed.
A fenderish layout should work fine for your project. You may consider to avoid the Fender doghouse for filter caps and place the caps where they supply the stages.
having all tubes in a row on the back of the amp and a cooling vent on top of the headshell right above the tubes makes cooling a busy amp much easier (and it helps to follow Richard's forensic analysis)
Another great source for layout tips is the Valve Wizard .
I always follow their rules and never failed.
A fenderish layout should work fine for your project. You may consider to avoid the Fender doghouse for filter caps and place the caps where they supply the stages.
having all tubes in a row on the back of the amp and a cooling vent on top of the headshell right above the tubes makes cooling a busy amp much easier (and it helps to follow Richard's forensic analysis)
Re: Tube Chassis Layout
Thanks for this idea! I actually have all three of Kuehnel's I can't building design books, plus a few others. Not sure if I noticed that in the books but I'll check the website out so I have a better idea of a suggested way of getting this all laid out.
It is a busy design, but I figured if I was going to build it, I'm going to build it the way I want it. The idea of building a 5 watt Fender Champ, sort of liking it, and then having to go out and buy more parts to build something I wanted didn't interest me.
It is a busy design, but I figured if I was going to build it, I'm going to build it the way I want it. The idea of building a 5 watt Fender Champ, sort of liking it, and then having to go out and buy more parts to build something I wanted didn't interest me.
Re: Tube Chassis Layout
My thoughts were not to start with a simple amp and make it more complex later. This won't usually work for various reasons. It was the other way round. Check out a proven Amp as an inspiration that has all the bells and whistles you need, learn why it has the layout it has and adapt it to your needs.
As far as I remember this is your first project and trying to reinvent the wheel with limited experience is begging for trouble.
You can do what you want, of course, but you asked for advice...
As far as I remember this is your first project and trying to reinvent the wheel with limited experience is begging for trouble.
You can do what you want, of course, but you asked for advice...
Re: Tube Chassis Layout
Your advice as well taken! I did go to the link and look through that, and have started to investigate some of the Fender amps, specifically their layout. Trust me, I do not want to reinvent the wheel, just looking for some guidance that I can use to fit what I'm trying to put together. Everything everyone is mentioned on here is very valuable!
Re: Tube Chassis Layout
I have used Ceriatone Layouts as a guide to build some of my amps. They have pictorial layouts for most of their amps. I have always had good results following their layouts.
Mike
Mike
Re: Tube Chassis Layout
Hadn't heard of that before but bringing up Google right now!
Re: Tube Chassis Layout
I disagree on the EFx loop. Delay/ time based effects sound best in a loop post EQ and gain. Dirt.pedals excel in the front end. Only 2 triode sections are needed. One for recovery and one for a cathode follower, to drive the cables without loss of treble. The 12DW7/ECC832 is perfect for this task. One side is half a 12AX7 for the recovery amp. The other section is half a 12AU7 for the cathode follower send side.
Tube junkie that aspires to become a tri-state bidirectional buss driver.