#183 build attempt

[Colossal]

Very nice. I confess to having done the same in the past.

Out of curiosity, did you measure the capacitance of your DIY coax?

[coolidge]

Beautiful! Very, very clean. I'm exhausted just looking at it!

I was surprised how much effort this build was, I really needed a break after. I can rip through a Marshall build like a surgeon but this style amp man a lot of work.

Yes, exactly. Dumble builds are very labor intensive and the build order of layering things from the chassis deck up must be observed, otherwise there is rework accompanied with a lot of swearing. The neater and more stark they appear, the greater the effort that goes into it! I am gearing up for another 102 build myself.

Beautifully done though! As much art as science

Let us know how it sounds! I'm interested to hear your impressions on your part choices.

You are spot on I made several laps around the chassis layering. HIGH potential for mistakes due to completing sections over several passes. I found a couple, it spooked me so I'll go ever every inch of this build before I power it up. Ha yeah I may have cussed a few times during this build. lol

Is the 102 a 6L6? I snagged a NOS quad of JAN Philips 7581A's and want to build another D style for those tubes and less snarl. Hopefully a better fit for humbuckers, I built the #183 for single coils.

[coolidge]

Very nice. I confess to having done the same in the past.

Out of curiosity, did you measure the capacitance of your DIY coax?

I did indeed, 10pf over 12 inches. Difficult for both my multimeters to measure capacitance that low, there was some fluctuation between 10-14pf but mostly settled at 10pf.

[Colossal]

Very nice. I confess to having done the same in the past.

Out of curiosity, did you measure the capacitance of your DIY coax?

I did indeed, 10pf over 12 inches. Difficult for both my multimeters to measure capacitance that low, there was some fluctuation between 10-14pf but mostly settled at 10pf.

Quite low!

Is the 102 a 6L6? I snagged a NOS quad of JAN Philips 7581A's and want to build another D style for those tubes and less snarl. Hopefully a better fit for humbuckers, I built the #183 for single coils.

Yes, #102 is Robben Ford's amp and uses 6L6s

[xtian]

"Made my own co-ax." Sure, me, too. Also, I mined and smelted all of the Aluminum for the chassis.

[Aaron]

Beautiful build. There’ll be no vibration in those boards, how thick is the PCB?

Aaron

[coolidge]

Beautiful build. There’ll be no vibration in those boards, how thick is the PCB?

Aaron

They are .125 inch thick FR4 with 2 oz copper. Trivia, I once tried to separate a preamp board from a power supply board with a scroll saw when the factory failed to separate them...half way across all the teeth had worn off the scroll saw blade.

[fred.violleau]

I am just amazed at the level of details. I really enjoy the up and flat layout of some of the resistors, I gives this build a fantastic 3D perspective. Can't wait to hear this caps! What had you pick those square small caps? Sound quality? Reliability? Design?

Cheers,

Fred.

[coolidge]

I am just amazed at the level of details. I really enjoy the up and flat layout of some of the resistors, I gives this build a fantastic 3D perspective. Can't wait to hear this caps! What had you pick those square small caps? Sound quality? Reliability? Design?

Cheers,

Fred.

Regarding the vertical resistors I stole that idea from a Marshall amp. I had already had the chassis made and sized for a previous board with smaller caps when I decided to use those huge aluminum body film and tin foil caps. I went vertical with the resistors due to those caps chewing up so much of the board space. I'm still surprised I was able to cram it all in.

Those square film caps are WIMA film/foil. I have had issues with silver mica leaking DC in the past so have cut over to film/foil for those caps which will last pretty much forever.

[coolidge]

Surprised no one has noticed I flipped the amp upright ala Marshall and moved the on/off switch to the front. Sacrilege?

oco219.jpg

[didit]

Surprised no one has noticed I flipped the amp upright ala Marshall and moved the on/off switch to the front. Sacrilege?

Noticed it. Don’t care but not a purist.

Best .. Ian

[pompeiisneaks]

Wait what? You can't do that, all the electrons will fall out!

Looks great to me

~Phil

[Aaron]

Surprised no one has noticed I flipped the amp upright ala Marshall and moved the on/off switch to the front. Sacrilege?


oco219.jpg

I noticed the transformer layout, Marshall style compared to the Fender/Dumble style.
Keen to hear some clips of this beast.

Aaron

[coolidge]

I noticed the transformer layout, Marshall style compared to the Fender/Dumble style.Keen to hear some clips of this beast.Aaron

I'm powering her up for the first time this weekend. Got all the vintage Mullards through the new tube tester last week.

If everything checks out with the new production Svetlana's I'm going to try this 1963 quad of Mullard EL34 OO getters. 58 years old and tested 20% stronger than the brand new Svetlana's

mullard.jpg

tubes01.jpg

tubes02.jpg

[coolidge]

Also ordered a 4x12 cab for this amp today from Guitar Cabinets Direct. Like this but with Mesa black taurus tolex. I have a quad of Celestion G12H-75 Creambacks at the ready.

gcd412.jpg