Tweedle Dee Deluxe and Tweedle Dee Champ

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tictac
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Re: Tweedle Dee Deluxe and Tweedle Dee Champ

Post by tictac »

Like I said before, no big deal.... I actually learned something since I didn't really know what a 5C3 circuit was the curiosity made me look into the subject a bit more....

Thanks for your input...

TT
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glasman
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Re: Tweedle Dee Deluxe and Tweedle Dee Champ

Post by glasman »

lovetone wrote:Nice layout very clear :D

Has anyone come with a good way to set the PI balance pot?
Didn't see anyone answer this, so here is my take. I would adjust it the same way Alexander did on his other amps. Adjust the pot for minimum harmonic distortion as measured at the speaker. Easy to do if you have the right equipment.

I would inject the reference signal into the phase inverter, might even lift the input and feed it directly or through a .1uf or larger cap. I use a spectrum analyzer to do these type of measurements.

Gary
Located in the St Croix River Valley- Afton, MN
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Charlie Wilson
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Re: Tweedle Dee Deluxe and Tweedle Dee Champ

Post by Charlie Wilson »

I suppose if you did not have a spectrum analyzer or harmonic distortion analyzer, you could inject a signal and balance measuring at power tube grids. Then tweek by ear. Not as accurate as Gary's method but it would get you close. I am curious though, I know a lot of guys like to balance the PI at a output wattage close to were they play the amp at gigging volume. Would you be able to inject enough signal at the PI with a typical signal generator to achieve this?
CW
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glasman
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Re: Tweedle Dee Deluxe and Tweedle Dee Champ

Post by glasman »

Charlie Wilson wrote:I suppose if you did not have a spectrum analyzer or harmonic distortion analyzer, you could inject a signal and balance measuring at power tube grids. Then tweek by ear. Not as accurate as Gary's method but it would get you close. I am curious though, I know a lot of guys like to balance the PI at a output wattage close to were they play the amp at gigging volume. Would you be able to inject enough signal at the PI with a typical signal generator to achieve this?
CW
I would suspect so, most signal generators produce in excess of 1V rms and that is usually more than enough to take the power about into clipping.

I have an old Philips PM-???? that produces upwards of 20V rms into a reasonable load (50 ohms). I will have to build a Tweedle Dum amp see how that power amp reacts. Never tried it, but will be fun to experiment with.
Located in the St Croix River Valley- Afton, MN
About 5 miles south of I-94
aka K0GWA, K0 Glas Werks Amplification

www.glaswerks.com
Kitarist
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Re: Tweedle Dee Deluxe and Tweedle Dee Champ

Post by Kitarist »

Music has to breathe and sweat. You have to play it live

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Sone Aura
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Old HP audio sig gens.

Post by Sone Aura »

Some of the old vac tube HP signal gens would put out as much as 5 volts peak to peak. That was vacuum tube era, so those were all voltage amps. Soiled state, except FETs are mostly current amps. If you have little B&K signal gen, or Wun Hung Lo Chinese made whatever, a single chip preamp, and a mono FET chip amp will work a treat for injecting lots of signal. Old vac tube HP distortion analyzers used to be found very cheaply too. $20-$50+ shipping, but most of those also do modulation and RF distortion too, so you need to know how to read some of those old boat anchors. I went to USB software defined analyzers for AF and I just did a kit for ham radio RF in the HF and VHF bands and am starting to build one using NXP semicons for UHF up to SHF & LHF (20GHz). Originally I got my ham licenses & now a GROL, mostly for access to the hamfests and swap meets, but it has opened a lot other doors for me too. The swap meets are great. Where else can you buy a transformer set for a 30 watt Gibson stereo GA79RTV for $3, and a giant sheet of copper shielding for 5o cents? I have bought $2000 worth of finger stock for $5. Run that around the edges of a sensitive preamp chassis lid, and it's shielded. The USB kit stuff is routinely sold by enterprising hams, and some of the stuff is actually pretty awesome. They usually have great aspirations of making money, which rarely happens, so when your USB analyzer breaks you buy one from the next delusional engineer.
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pompeiisneaks
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Re: Tweedle Dee Deluxe and Tweedle Dee Champ

Post by pompeiisneaks »

I am about to build one of the Tweedle Dee Deluxe's from a salvaged PT/OT from an old Philco radio/turntable, with OS RCA tubes etc. I thought I'd put together a BOM in xls format so I could account for all the components. Please let me know if you see errors, I'll update as needed.
TweedleDee-BOM.xlsx
~Phil
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Stephen1966
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Re: Tweedle Dee Deluxe and Tweedle Dee Champ

Post by Stephen1966 »

Just out of curiosity and in case anyone is interested, I've drawn up the board drilling template for the Tweedle Dee. If anyone is going to attempt building this into a 5E3 shell, be aware that this board is for a 5C3 and only has one grid stopper on the single INST/NORMAL input.

I've assumed Imperial measurements throughout except for the Piher (H05) PI trimmer which is spaced 10mm apart for the outer pins and 5mm off centre for the wiper pin. I've also assumed MrD used a standard Fender board size of (LxH), 8.75" x 3". I performed some testing of the scale using actual measurements from components on my desk, like the big Ruby caps and the trimmer and the board size is very close.

After a little straightening up and lens correction in Photoshop I've also included the photo of the board in the bottom layer of the pdf. You can activate this by going into the layers in acrobat or reader. I didn't get the photo perfectly straightened out, but close enough to be indicative of the actual placement of holes.

Eyelet holes are all 1/8" diameter. If you are working in metric you will need to get a 1/8" bit because 3mm is too tight and 3.5mm too loose. The through holes have all been marked at 3/32" though if you are using metric, 2mm or 2.5mm would suffice. Similarly, the mounting holes (assuming 1/8" screws) have been marked at 3/16"; 3.5mm would be very snug but 4mm would allow for a little tweaking better.

I personally, wouldn't be able to use this but if you are hot on making a thoroughbred (5C3) Tweedle-Dee, let us know how it goes.

The pdf attached is formatted to Letter size but whether you are printing on US or European paper sizes if you set it to print at 100% you should get the correct size. You can double check it by measuring the dimensions marked on the print.
Tweedle Dee Board (board working copy).pdf
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Stephen
www.primatone.eu
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