5E3 Head Build

bikescene

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I just finished wiring up a 5E3-based head build late last night. I had shared a couple of photos in one of the recent work in progress threads, and wanted to share the results.

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I had bought a Classictone 40-18066 upright PT (330-0-330 secondary) and 40-18022 OT (8k:8ohm) when it was announced that Classictone was stopping production. I chose to mainly use metal film resistors as an experiment. I used three 22uF filter caps, since that seems to be the recommended modern setup. All installed in an oversized Hammond 1444-22 chassis, so I could also add a Hammond vented cage for that lunchbox amp look.

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I mainly used the Rob Robinette’s 5E3 page and old posts from this forum as reference to wire it all up. I split the power grounds from the preamp grounds based on Rob’s modern 5E3 layout.

I only checked the voltages at the filter caps: 382V, 329V, and 241V from a wall voltage of 121V. I used JJ 5Y3 and 6V6 tubes in the power section. I didn’t measure the tube pins because of the excitement of having an operational amp at power up. I may investigate lowering the B+ in the future. Any suggestions or links to old threads would be appreciated.

I finished my build at around midnight, so I had to test the build out through a Suhr Reactive Load through impulse responses. In the clip below, I played a few open chords on a guitar equipped with a GFS Mean 90 bridge pickup. I used IRs of my speakers: Weber Ceramic Blue Dog in a 1x12, Eminence GA10-SC64 in a 1x10, and finally a Jensen C10Q in a 1x10 cab. Tone was maxed, and the bright volume was at 12:00.


The main mod I added was switchable NFB: a pot in series with a resistor to go from 27k to ~47k. I haven’t tried this out yet, and experiment with getting that NFB resistor value up to 56k in the future.
 

bikescene

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That looks nice, where did you get the turret board/ parts kit from?
.
Thanks. I bought the turret board off of ebay. A lot of the hardware (nuts, bolts, tube sockets, jacks, wire) were from Valvestorm. The chassis/resistors/capacitors were from Mouser. The transformers/tubes were ordered from Tube Depot.

I ordered the Valvestorm/Mouser parts when I did a Plexi build of the same nature.
 

nathan5782

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.
Thanks. I bought the turret board off of ebay. A lot of the hardware (nuts, bolts, tube sockets, jacks, wire) were from Valvestorm. The chassis/resistors/capacitors were from Mouser. The transformers/tubes were ordered from Tube Depot.

I ordered the Valvestorm/Mouser parts when I did a Plexi build of the same nature.

I got my 5E3 parts kit from eBay too (tubeaudiosupply) and the chassis from Antique Electronics supply. The Belton power tube sockets didn't fit so I had to get some ceramic ones.
 

bikescene

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I got my 5E3 parts kit from eBay too (tubeaudiosupply) and the chassis from Antique Electronics supply. The Belton power tube sockets didn't fit so I had to get some ceramic ones.
I went back through my records, and saw that I bought 5F1 and 5E3 boards from the same eBay seller.

I had the Belton sockets in mind when I decided to punch my own chassis. I kept procrastinating with the chassis drilling though, and put it off for more than a year. I may just go with a kit in the future, and just focus on the building.
 

dan40

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Cool looking resistors,

The cmf60 resistors are very nice and I use them quite often in my builds. These rn65's are from the same manufacturer but they are slightly larger and closer in size to what we normally see in tube amps. The data sheet list them at 1/2 watt also, but I have read that they are actually 1 watt. Due to the fact that they are mil-spec, they drop the rating down to 1/2 watt to satisfy military specifications.

https://www.digikey.com/en/products...m4TRdHAFtVfYDkDsTUhUcSlEt5tTuulsaAmPUEALw_wcB
 

jsnwhite619

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I think my picks would be Jensen, Eminence (though a close match), and the Blue Dog a few places behind them. The Jensen seems to have the warmth and the presence while the others seem to miss one or the other.
 

bikescene

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Posts
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Location
New York
The cmf60 resistors are very nice and I use them quite often in my builds. These rn65's are from the same manufacturer but they are slightly larger and closer in size to what we normally see in tube amps. The data sheet list them at 1/2 watt also, but I have read that they are actually 1 watt. Due to the fact that they are mil-spec, they drop the rating down to 1/2 watt to satisfy military specifications.

https://www.digikey.com/en/products/detail/vishay-dale/RN65C2500BB14/3193933?utm_adgroup=Through Hole Resistors&utm_source=google&utm_medium=cpc&utm_campaign=Shopping_Product_Resistors&utm_term=&utm_content=Through Hole Resistors&gclid=Cj0KCQiA47GNBhDrARIsAKfZ2rAR8Fs3d9VMeJL8ytK3NpKm4TRdHAFtVfYDkDsTUhUcSlEt5tTuulsaAmPUEALw_wcB

I like all of the Vishay Dale offerings. A big plus is that the values are printed on the resistor body. It was easier to keep track of components that way. I also used a RN65 resistor for the V1 cathode because of its long leads. I also used the CPF series where I needed higher power ratings.

I think my picks would be Jensen, Eminence (though a close match), and the Blue Dog a few places behind them. The Jensen seems to have the warmth and the presence while the others seem to miss one or the other.

Thanks for checking it out. I’d like to pair the amp with an appropriate 12” Jensen or Weber one day.
 

jsnwhite619

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I like all of the Vishay Dale offerings. A big plus is that the values are printed on the resistor body. It was easier to keep track of components that way. I also used a RN65 resistor for the V1 cathode because of its long leads. I also used the CPF series where I needed higher power ratings.



Thanks for checking it out. I’d like to pair the amp with an appropriate 12” Jensen or Weber one day.

If you want loud and full, a Legend 1258 sounds fantastic with a 5e3. This one had maybe half dozen simple, normal mods for smoothing things out and cutting some bass, but nothing too crazy - all stuff found on Rob's site. It ended up being pretty loud, but sounded great.

 




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