Tweedle Dee, Take two

[fred.violleau]

Got a quick question :
My initial plan was to use a humdinger. So I would have left out the center tap and use the humdinger grounding.
Refering to Rob Robinette's website it supposedly works better than a Centre Tap to reduce PT hum.

But If I use the mosfet reducer, I should connect it between the ground of the bridge rectification and chassis ground rather than High voltage Center Tap right?

Thanks,

Fred.

[CaseyJones]

I chose to get away from a well paved way and may do mistakes. I hope these will be valuable lessons indeed as we learn from our mistakes (at least I do, or try to).

You may or may not like what I am trying to do here and that is fine with me. Thanks for sharing your point of view.

It's not about like or dislike. I've built enough of these I have to take my socks off to count. Every time I build another I come back to how simple and well conceived the "original" is.

It's a simple amp that's well matched to a good guitar. It goes from clean to dirty by touch like a Trainwreck. The gain and EQ are nicely dialed- in as-is.

I tried a few things such as a switchable BF channel with a TMB tone stack. It sounds o.k., maybe a little dry as in "needs reverb". Bad news is the Dumble voiced clean tone just kills the "iconic" BF tone, no reverb required.

It's like the difference between a Lotus and a mini- van. With a mini- van you add flat screen TVs and cupholders until it's "perfect". With a Lotus you eliminate parts until all that's left is four tires and a place to sit.

[ChopSauce]

Personally, I'd be tempted to strip down my mini-van until it handles like a Lotus, and then add the items I like most ...
(including a sofa and a sound system!)

My understanding of Fred's build is that his amp shouldn't be considered much of a Tweed Deluxe, but rather a platform for mods/testing/?!. with a minimal number of tubes and one of the simplest push-pull power section ...

Bad news is the Dumble voiced clean tone just kills the "iconic" BF tone, no reverb required.

I wish I got it...

... & thank you very much for sharing your experience ...

[norburybrook]

I chose to get away from a well paved way and may do mistakes. I hope these will be valuable lessons indeed as we learn from our mistakes (at least I do, or try to).

You may or may not like what I am trying to do here and that is fine with me. Thanks for sharing your point of view.

It's not about like or dislike. I've built enough of these I have to take my socks off to count. Every time I build another I come back to how simple and well conceived the "original" is.

It's a simple amp that's well matched to a good guitar. It goes from clean to dirty by touch like a Trainwreck. The gain and EQ are nicely dialed- in as-is.

I tried a few things such as a switchable BF channel with a TMB tone stack. It sounds o.k., maybe a little dry as in "needs reverb". Bad news is the Dumble voiced clean tone just kills the "iconic" BF tone, no reverb required.

It's like the difference between a Lotus and a mini- van. With a mini- van you add flat screen TVs and cupholders until it's "perfect". With a Lotus you eliminate parts until all that's left is four tires and a place to sit.

Casey do you build your 5E3's into original sized combos? I ask because I built mine as a head and into a separate 1x12 speaker it has way too much bottom end that you can't dial out as it only has a tone control. In a small open combo that extra low end isn't there so its not an issue except when the amp is dimed and you get that fuzz OD Neil Young likes so much

I love my tweedle Dee head and use it more than any other amp in the studio but I had to reduce the bass significantly with the cap values similar to Fred.

M

[fred.violleau]

I guess we all agree that simplicity is the utmost refinement. And I totally agree that stock Tweedle Dee is a great amp. I would stay on the bright side though and enjoyed the subtle interaction of the volume pots as well.

I think some of those mods add a lot to this great amp, but again it is very personal, mostly NFB and bypass Cap on V2A. I personally loved the cascade switch but you need to add some mods in order to keep things under control.

And that is were it starts to derail from the original plan. So this amp is not a Tweedle Dee anymore, but something else, and it is one of the best little amp I have ever played. My purpose here is just to share what I came up with. Some may like it. But I agree that you should build a stock Tweedle Dee.

EDIT: and BTW, what purpose would it fit if it were not to satisfy my needs as a player first? After all, building amps is a luxury that allows me to learn, and get what my ears want to hear after all

Fred.

[CaseyJones]

I love my tweedle Dee head and use it more than any other amp in the studio but I had to reduce the bass significantly with the cap values similar to Fred.

M

After spending literally 1000 hours staring at TD guts and I'm using "literally" literally... I've come to appreciate Dumble''s little monster as a carefully thought out recipe. I looked at the TD thread here and cloned it initially. That was the first 50 hours. The next 950 hours were spent contemplating how and why it is what it is.

It's like watching old Kung Fu movies, "Kill Bill" (part one?) or old Star Wars featuring Yoda, Dumble being Yoda. As the all knowing amp guru and Amp Fu master I expect he enjoys seeing the rest of us whacked with a stick so to speak. Repeatedly. Especially considering his legendary disdain for "Amp Pirates".

My TD builds have all been combos.

Returning to Dumble the man is not without a sense of humor. Take for example the wad of resistors in the bias network. I might have taken it a few steps further an used an elaborate series / parallel arrangement to stimulate online commentary and critique.

Another clever twist is the Rocket 50 in the TD. While the rest of us are squandering our parts budgets on expensive Blues, Golds and Creams Mr. Fu used a laughably inexpensive speaker to great effect.

[norburybrook]

I love my tweedle Dee head and use it more than any other amp in the studio but I had to reduce the bass significantly with the cap values similar to Fred.

M

After spending literally 1000 hours staring at TD guts and I'm using "literally" literally... I've come to appreciate Dumble''s little monster as a carefully thought out recipe. I looked at the TD thread here and cloned it initially. That was the first 50 hours. The next 950 hours were spent contemplating how and why it is what it is.

It's like watching old Kung Fu movies, "Kill Bill" (part one?) or old Star Wars featuring Yoda, Dumble being Yoda. As the all knowing amp guru and Amp Fu master I expect he enjoys seeing the rest of us whacked with a stick so to speak. Repeatedly. Especially considering his legendary disdain for "Amp Pirates".

My TD builds have all been combos.

Returning to Dumble the man is not without a sense of humor. Take for example the wad of resistors in the bias network. I might have taken it a few steps further an used an elaborate series / parallel arrangement to stimulate online commentary and critique.

Another clever twist is the Rocket 50 in the TD. While the rest of us are squandering our parts budgets on expensive Blues, Golds and Creams Mr. Fu used a laughably inexpensive speaker to great effect.

Indeed and I'm tempted to make another with the rocket 50 and the correct size cabinet for this reason I do love where I've ended up with my head though along with the cream Alnico 1x12.

Mr Dumble realised the average fender values were too bass heavy for 'proper speaker cabinets ' and loud playing and reducing the bass with the 4.7uf bypass caps is a great way of keeping things under control at volume. Most fender combos have really open backs so you need extra bass in the amp to compensate for the complete lack in the cabinet.

However I have a project that's been in the works for a year now and I've still got no time to make it as I'm too busy in the studio with projects so the HAD tweedle dee combo in all it's original form will have to wait

M

[fred.violleau]

First weekend in Montreal with temperature rising above 10 degrees in the last 5 months. Needless to say we spent time outside! So the build did progress, but slowly

Had the power tube wired with the fixed/cathode bias switch. Worked on the bias filtering and relay power board.

PXL_20210322_121311445.PORTRAIT.jpg

PXL_20210322_120226268.jpg

Created a "platform' to receive line filtering and inrush reducer to sit on top of the PT. I received the MOSFET B+reducer components, but the jury is still out on where I should position it...

PXL_20210322_120908312.jpg

PXL_20210322_121324166.PORTRAIT.jpg

I am trying the RG59 for the long cable runs... We'll see how it goes. I had forgotten how big the cable is..

Have a good week!

Fred.

[CaseyJones]

Hi guys,

This is my second take on this great build. First one sounded absolutely fantastic, so I needed a new one since the first one found a new home.

I did many layout for this build in order to balance feature set and size. I ended up with a 12x8x2 Hammond chassis.

Mods are as follow:

Clearly a Robinette disciple. I should have said this the first time:

“Information is not knowledge.
Knowledge is not wisdom.
Wisdom is not truth.
Truth is not beauty.
Beauty is not love.
Love is not music.
Music is THE BEST.”

Robinette's site is a masterpiece of plagiarism. It will take you this far:

“Information is not knowledge."

While many of us are approximately here:

“Wisdom is not truth.
Truth is not beauty."

A precious few of us are here:

“Music is THE BEST.”

In general the best of us keep it close to the vest lest some offshore amp builder plagiarize our work and exploit it to circumvent a lengthy R&D process.


I would be hypocritical not to admit imitation is the sincerest form of flattery. Somewhat more obscure than F.Z.,

"It's too late
There's no one left that I even want to imitate"

The "Sharon Tate" reference whizzes right past more and more people every year.


O.P.,

Consider the Morgan Tweed 20. I haven't seen a schematic but I can guess what's inside. It's likely one channel of a 5E3 built around a 12AY7 driving a '60s Fender style long tailed pair using a 12AT7. TD aficionados can generate test platforms that illustrate the differences between PI types. If you're building a Switch-O-Matic w/ switchable NFB, FX loop, a dishwasher and the kitchen sink it may be a better starting point as opposed to ruining a perfectly good TD.

Soldano has always had a really nice buffered FX loop.

Many new (ish) builders make the mistake of using a tiny chassis for their early builds. IMO it's a further mistake to attempt to re- purpose scrounged parts as well. Too many variables to control. What we want is constants to use as anchors and pivot points.


Take a look at a Kendrick Climax some time. It was sold for a while as The New Joy Zee kit.

Gerald Weber hasn't built one lately.

Seems to me there is plenty of room inside an aftermarket Deluxe Reverb chassis for channel switching, FX loop(s), whatever.

[pompeiisneaks]

Hi guys,

This is my second take on this great build. First one sounded absolutely fantastic, so I needed a new one since the first one found a new home.

I did many layout for this build in order to balance feature set and size. I ended up with a 12x8x2 Hammond chassis.

Mods are as follow:

Clearly a Robinette disciple. I should have said this the first time:

“Information is not knowledge.
Knowledge is not wisdom.
Wisdom is not truth.
Truth is not beauty.
Beauty is not love.
Love is not music.
Music is THE BEST.”

Robinette's site is a masterpiece of plagiarism. It will take you this far:

“Information is not knowledge."

While many of us are approximately here:

“Wisdom is not truth.
Truth is not beauty."

A precious few of us are here:

“Music is THE BEST.”

In general the best of us keep it close to the vest lest some offshore amp builder plagiarize our work and exploit it to circumvent a lengthy R&D process.


I would be hypocritical not to admit imitation is the sincerest form of flattery. Somewhat more obscure than F.Z.,

"It's too late
There's no one left that I even want to imitate"

The "Sharon Tate" reference whizzes right past more and more people every year.


O.P.,

Consider the Morgan Tweed 20. I haven't seen a schematic but I can guess what's inside. It's likely one channel of a 5E3 built around a 12AY7 driving a '60s Fender style long tailed pair using a 12AT7. TD aficionados can generate test platforms that illustrate the differences between PI types. If you're building a Switch-O-Matic w/ switchable NFB, FX loop, a dishwasher and the kitchen sink it may be a better starting point as opposed to ruining a perfectly good TD.

Soldano has always had a really nice buffered FX loop.

Many new (ish) builders make the mistake of using a tiny chassis for their early builds. IMO it's a further mistake to attempt to re- purpose scrounged parts as well. Too many variables to control. What we want is constants to use as anchors and pivot points.


Take a look at a Kendrick Climax some time. It was sold for a while as The New Joy Zee kit.

Gerald Weber hasn't built one lately.

Seems to me there is plenty of room inside an aftermarket Deluxe Reverb chassis for channel switching, FX loop(s), whatever.

First, If I've misunderstood your tone, this is text after all, and a very difficult medium to convey emotions well, and I apologize.

I feel this seems pedantic at best, denigrating at worst, and don't get what it provides for the OP other than to say "stop trying to learn or better yourself, instead just do what I tell you"

I don't discount you have a wealth of knowledge, but by intentionally telling someone what not to do, you're not teaching them anything, and as I've found in my life most people, when told not to do something, will do it to find out why they shouldn't.

It is often better to suggest what you feel is a good course and leave it be, instead of moving to try to make them feel bad about themselves for not doing exactly as you mandated.

My 2c anyway. I think if you had just posted most of the above detailed information about topologies, which is super useful information without the 'talking down to op for ignoring your previous mandates' part it would be 100000x better advice.

If we can't treat one another with dignity, why try?

~Phil

[fred.violleau]

@Casey Jones

Consider the Morgan Tweed 20. I haven't seen a schematic but I can guess what's inside. It's likely one channel of a 5E3 built around a 12AY7 driving a '60s Fender style long tailed pair using a 12AT7. TD aficionados can generate test platforms that illustrate the differences between PI types. If you're building a Switch-O-Matic w/ switchable NFB, FX loop, a dishwasher and the kitchen sink it may be a better starting point as opposed to ruining a perfectly good TD.

I have paired a TD preamp with a LTPI and it sounds indeed very different. I have not heard the Morgan amp, so I can't tell.
Glad you have that knowledge, I am building mine and attend to do it with my ears as well.

Many new (ish) builders make the mistake of using a tiny chassis for their early builds. IMO it's a further mistake to attempt to re- purpose scrounged parts as well. Too many variables to control. What we want is constants to use as anchors and pivot points.

Very interesting, glad you shared that insight.

Take a look at a Kendrick Climax some time. It was sold for a while as The New Joy Zee kit.

Gerald Weber hasn't built one lately.

Seems to me there is plenty of room inside an aftermarket Deluxe Reverb chassis for channel switching, FX loop(s), whatever.

I was not aware of those amp, will definitely look into it!

Agreed for the space available in a deluxe reverb chassis, but it costs a lot more than the Hammond box...

As for all the plagiarism and the rest... I wish you shared more about constant and pivot points!

Thanks,

Fred.

[norburybrook]

Fred,

here you go:

new_joyzee_schematic_153.pdf

M

[fred.violleau]

Hey guys,

On the last miles here and I have a quick question:
I separated the two channels (Normal and Bright).
I switched V1a pot's input and output to improve V1A's load impedance. Did the same swap on the bright channel pot Install.
I wanted to confirm that I don't need the 220k mixing resistors since I have a relay that is avoiding the two channels mixing :

5E3-cascade-Switch.jpg

Thanks !

Happy Easter !

Fred.

[pompeiisneaks]

My general understanding was always that if you remove the mixing resistors it changes the tone of the amp. to attempt to keep it more closely to that sound, you'd want a 220k to ground for the channel that's active as well as the 220k inline. It still basically sends a 'signal path through' and the 'signal path back through the mixing resistor like it would have in the other channel'

I'm not 100% sure if this makes sense, but hope it does.

~Phil

[fred.violleau]

Hey Phil, thanks for jumpin' in!

Actually, there is no 220k mixing resistor in the original 5E3. Nor is there on the Tweedle Dee.
It is a recommended when eliminating the channels interaction.
My guess was as long as my relay implementation keeps the signals separated it should act as these resistors.
These 220k resistors are not ground related, they seem to limit the interaction between the two channels, so basically big enough so the signal does not follow that path, but not too big so they don't block the signal right?

But if they act as a voltage divider, they would still divide the signal by half so that is quite big...

Still confused over these..

Fred.