Best build for first timer.

[rockinmac]

I have some old Ao35's lying around or would it be best to order a kit from mojotone like a 5e3 or something to get my feet wet? I do have some knowledge in electronics and lead dress but i wouldn't say a lot. Thanks.

[Phil_S]

Rework/repurposing is always more challenging than building a kit from the ground up. There are lots of things a new builder doesn't "see." You might get lucky, though.

I'd start with something simpler than a 5E3. 2 or 3 tubes is plenty and look for a low parts count. Many start with something Fender-champish. Get a successful build under your belt. Work your way up in difficulty.

Reworking an AO-35 isn't out of reach. It will require some good planning. The A-35 can go either way, 5E3 or 18W lite. Have you ever played a Deluxe or a clone? It isn't everyone's cup o' tea.

[M Fowler]

I built a Marshall Lite IIB out of my AO-35 and that is a great little amp very loud for 18 watts. I wired the 12AX7 parallel.

Mark

[rockinmac]

Thanks for the info! i was wanting to start with a 5e3 first because i have a old jensen speaker p12q laying around i need to use. But i know i need to take steps. I have a swart AST so i LOVE the tweed sound. My two favorite amps are 2 that are Probably the most popular with the diy crowd. A 5e3 and a trainwreck express. BTW i will take ANY tips! THanks again!

[rockinmac]

or if you recommend a champ or princeton that would be fine to. A man can't never have to many tweeds!

[martin manning]

If a 5E3 is what you are after, then I'd go for it. It's not too complex for a first effort, and a complete Champ kit will not be that much less in cost particularly since you already have a speaker.

There is another first build thread here: https://tubeamparchive.com/viewtopic.ph ... highlight= The resources and descision process are worth a read, and the build guide I wrote up for that project (pg. 9 of the thread) will be generally applicable.

[rockinmac]

Alright sounds good I think I'll order the 5e3 kit this week I'm in the process of moving but maybe I can get a whole day where I can spend with it. Is the mojotone kit a good kit? I notice that the secondary voltages on the standard 5e3 PT seem a little high i guess if you had to you could drop them with a diode. I just can get the monotone a little cheaper. Thanks again!

[martin manning]

I've never actually seen a Mojo kit, but I believe they use good quality parts, and from what I read the cabinets are very good too. The instructions (available on-line) leave a lot to be desired, though. Take your time, and also take the time to understand the circuit as best you can as you go.

[rockinmac]

I know the voltages affect the tone. How will a higher voltage affect the tone compared to say a lower one? I the standard transformer has 384 vdc on the secondary and the low voltage one has 330 vdc. Seems like a big difference to me. Like I said it shouldn't be hard to drop that secondary or at least I wouldn't think.

[martin manning]

Interesting... these PT's are all over the place. I see Mojo's spec for their 756 is 384 VAC at 75mA, and Hammonds 290BX (claimed equivalent to Fender 125P23B original) is 330 VAC fully loaded at 138mA. Magnetic Components' 5E3 PT is spec'ed at 355 VAC and 100mA. Fender's '57 Deluxe (reissue) schematic shows 370 VDC at the reservoir, which would say that the secondary VAC should be much closer to 330 than 384. I tend to believe MC and Hammond are trying to replicate the original as best they can. Personally I would rather get the voltage right without having to resort to a Band-Aid fix.

BTW, another very good kit (maybe one of the best) is here: http://www.missionamps.com/5E3kit.shtml ...but $100 more.

[martin manning]

5E3 Tube Depot kit build documentary here with lots of good pictures: http://www.fender.com/community/forums/ ... 13&t=46716
Check out these inductors etched into the PCB on the grid side of the input resistors.

[M Fowler]

On the ordering page for the Mojotone 5E3 they give you the option to order the lower power PT 330v. EDIT NO OPTIONS SHOWN MY ERROR

http://www.mojotone.com/amp-parts/amp-kits-tweed-style

I could not find the 768SP under transformers but found this one below which out of stock.

http://www.mojotone.com/amp-parts/amp-t ... Mda--TonSg

[martin manning]

768SP is an output transformer with multi-tap secondary. http://www.mojotone.com/amp-parts/trans ... -Secondary The export version of the PT (out of stock at present) has the correct voltage, but then you have to deal with all the extra leads. I also see from their spec sheet that it is rated at 0.075mA!

On the OT spec sheet, thay have (again) labeled each half of the primary as 4k... so making it a 16k Za-a. Not!

[M Fowler]

Geez I better go get another cup of coffee Martin, I really feel dumb now Transformer: MOJO768 - 8 ohm tap -or- MOJO768sp - 4/8/16 ohm taps

I'm sure it won't be my last stupid act of the day!

Mark

[rockinmac]

How bad will that high voltage affect the tone. I can get the mojotone clone at wholesale price. I may order the kit and then order a classic tone PT. Thanks!