Contemplating starting a #102 build, a few questions

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Ang3lus
Posts: 243
Joined: Sat Oct 29, 2011 8:53 am
Location: Israel

Contemplating starting a #102 build, a few questions

Post by Ang3lus »

Hello all,

I'm contemplating starting a 102 build soon (starting in 3 weeks i reckon and i have a few questions before hand.

what is the job of the diode in the heater and the resistor in the heaters ? balance the heaters to 12.6v? and the 100r to ground are faux center tap i presume ?

2. do anyone have a BOM of the #102 ?

3. any recommended build threads that show the 102 being built ?
groovtubin
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Re: Contemplating starting a #102 build, a few questions

Post by groovtubin »

Ang3lus wrote:Hello all,

I'm contemplating starting a 102 build soon (starting in 3 weeks i reckon and i have a few questions before hand.

what is the job of the diode in the heater and the resistor in the heaters ? balance the heaters to 12.6v? and the 100r to ground are faux center tap i presume ?

2. do anyone have a BOM of the #102 ?

3. any recommended build threads that show the 102 being built ?
Shalom dude! Thats probably the LED PILOT light power suppy UR looking at! Go to DUMBLE FILE SECTION< ALOT of layouts and formats to build 102!

Jim@Omegaamps.com
Ang3lus
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Location: Israel

Re: Contemplating starting a #102 build, a few questions

Post by Ang3lus »

then is it really needed ? isn't it just easier to use a CT with the heaters and a normal 12.6v lamp ? (that's how i did it in my last SLO type build, instead of a faux CT).

and to save myself from another transformer, can i just use a 6vac-6vac tap ? (I custom wound my PTs at a local shop here)
groovtubin
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Re: Contemplating starting a #102 build, a few questions

Post by groovtubin »

Ang3lus wrote:then is it really needed ? isn't it just easier to use a CT with the heaters and a normal 12.6v lamp ? (that's how i did it in my last SLO type build, instead of a faux CT).

and to save myself from another transformer, can i just use a 6vac-6vac tap ? (I custom wound my PTs at a local shop here)
NO other tranny is needed, you take a fwd biased diode into a 330 ohm resistor off ONE 6VAC leg, into the LED anode, and send the cathode of LED back to other leg of 6VAC! All there is to it!

jim
Ang3lus
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Re: Contemplating starting a #102 build, a few questions

Post by Ang3lus »

oh, hehe, sorry man, what i meant was

the 6-6 winding to replace the 6-0-6 transformer that powers the relay.

isn't it better just to use a tap than a small transformer ?
groovtubin
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Re: Contemplating starting a #102 build, a few questions

Post by groovtubin »

Ang3lus wrote:oh, hehe, sorry man, what i meant was

the 6-6 winding to replace the 6-0-6 transformer that powers the relay.

isn't it better just to use a tap than a small transformer ?
The BIG reason for a separate relay tranny is NOISE!!!!!!!!!! LOTS OF it no matter how well you filter it! HAD knows best! ;)

jp
Ang3lus
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Re: Contemplating starting a #102 build, a few questions

Post by Ang3lus »

oh, thanks for the explanation, i thought about the noise issue, but i just finished a high gain slo clone with relays and even with a transformer tap i get hardly any noise :)

thought a dumble would introduce even less noise, guess i was wrong :)
amplifiednation
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Re: Contemplating starting a #102 build, a few questions

Post by amplifiednation »

Ang3lus wrote:oh, thanks for the explanation, i thought about the noise issue, but i just finished a high gain slo clone with relays and even with a transformer tap i get hardly any noise :)

thought a dumble would introduce even less noise, guess i was wrong :)
My last build used a bassman PT and the 5v rectifier tap is powering two relays just fine. It isn't any noisier than the build I did with 100 twin iron and aux transformer.

I would go for the extra transformer tap, save the space
Amplified Nation
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Structo
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Re: Contemplating starting a #102 build, a few questions

Post by Structo »

Most power transformers don't have a separate tap for the relay supply.

Herr Dumble used mostly Fender power transformers and output transformers in his builds.

They don't have a separate winding for the relay supply so he added a filament transformer for it.

Check out the layout and schematic of the #124 ODS amp.

This is the amp that was reverse engineered that got all the clones started.

To stay true to Dumbles design you should follow that layout as close as possible.
Don't stray too far from the original or you can lose that Dumble tone.
In other words, don't use carbon comp resistors or other vintage parts.
Use what Dumble used within reason.

Especially the grounding scheme.
Also try to use the same component selection, particularly the resistor selections.
Meaning, use the Dale Rn65 plate resistors and the KOA carbon film resistors elsewher.
Use Metal Oxide resistors in the power supply for the dropping string.

I built a 100w ODS amp based primarily on #124 although I went with high plates and the Skyline tonestack.
I mixed some of #102 and #183.

Frankly, the original #183 (EL34 based power amp) is among the best Overdrive Special specimens known.

Look in the Dumble Files section for the layouts.

Not sure how difficult it will be to source parts from Israel but I wish you the best.

Shalom
Tom

Don't let that smoke out!
Ang3lus
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Re: Contemplating starting a #102 build, a few questions

Post by Ang3lus »

Thanks Tom, since i'm winding my PT at the shop anyways, i will use a seperate tap and save the space.

from what i hear in the clips, i like the 102 better than the 183, it has more "character" than the 183 to my ears.

it could be just "tone of the moment" thing, since sometimes the 183 sounds better than the 102.

I will build both maybe :)
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Structo
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Re: Contemplating starting a #102 build, a few questions

Post by Structo »

I had built mine like #102 but there were certain aspects I didn't care for so some of #183 crept in.

I can't remember all that I did but it suits my style more now.
Still has 4x 6L6.

Also remember that these are gigging amps and meant to play at a louder level than bedroom playing.
This is one of the reasons I built a Dumbleator, to be able to turn up the volume and master to get more tone at lower levels.
Plus it works real well to incorporate time based effects into the loop.
Tom

Don't let that smoke out!
Ang3lus
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Re: Contemplating starting a #102 build, a few questions

Post by Ang3lus »

Why is the dumble loop needing such a device as the dumbleator ?

do you think a dumbleator would work well for the SLO or such ?
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Structo
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Re: Contemplating starting a #102 build, a few questions

Post by Structo »

It would work good for any amp that has passive loop jacks.

That is, send and return from the preamp to poweramp.

It is a tube buffered effects loop.
Tom

Don't let that smoke out!
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