Newbie(me) buys old PA amp w/ A-3801 Stancor

[DjunDjunMaster]

I'm a complete novice to building amps and aside from GK's clips and CD haven't any experience hearing Trainwreck Express amps, but I like what I hear so I bought this old behemoth with a Stancor A-3801 OT in it.

Looking at the Express schematics, I don't see any that are particularly for the utilization of the Stancor. Is there one, or do you just use it in place of the currently available iron specified? I'd like to start putting together a parts list and considering what I need to sell to fund this project. Correct parts preferred.

Thanks for the help, and apologies for the ridiculous username. I play games with 20 sided dice, and like palm-muted distortion.

[sliberty]

The 3801 would be used in place of the various Heyboer or Pacific output transformers that you might see listed.

[Cliff Schecht]

You may be better off not building an Express for your first build. It's a very involved build and requires a good amount of practice with a drill press, soldering iron and in general knowing how to safely build an amplifier. Some of the techniques Ken Fischer used are great when done properly but one bad solder joint can easily take out your expensive transformers and ruin a lot of other components as well. I would recommend you start on something simpler or perhaps find a kit that you can start on, this way you'll have some practical experience building an amplifier before you tackle such a tedious project..

You say you're a novice. How much do you know about how a guitar amp works inside? You don't have to understand all of the electronics and what not but you do need to understand and know how to implement the safety features of an amplifier like properly fusing, grounding the power plug to the chassis and how to safely strip and wire the solid core wire without nicking it or weakening it in other ways. There are LETHAL voltages inside of a tube amp that you'll need to learn about and respect, otherwise you could hurt yourself badly..

[geetarpicker]

The earlier wrecks prior to around mid '89 used the off the shelf Stancor 3801, at least in the Express I'm not 100% sure on the Liverpool. So you can think of the 3801 as an original TW transformer. That said, my original Express was made a little later in '89 and was one of the first with Pacific transformers.

[MCK]

Any one know what the pre-89 PTs were matched to the S3801 in an Express? Thanks for the info

[DjunDjunMaster]

Thanks for chiming in everybody, and GK thanks for the personal knowledge on the timing of the swap!

I looked at some of the recommended beginner amp kits mentioned elsewhere on the board; I wonder if there's a specific one that is likely to hold it's value or be most desirable? I will be sure to take care in any event, and appreciate the concern, Cliff!

-Josh

[sliberty]

If you are looking for a beginner kit, consider building a Champ or a Princeton. You will find that these amps are good learning experiences, very doable for a first build, and will serve a useful role in your amp collection. As for holding value, most home built amps are more costly than most mass produced, made in China, sold in GUitar Center amps. So, don't think of building your own amp as a proposition that has a financial justification. FOr example, you can probably buy an AC30CC head for less than it costs to build a Rocket. But the thrill of playing though your own creation, and the intellectual excersize of learning about amps and then being able to modify them to taste - those things are priceless.

Just be careful - you will get hooked, and you will spend more than you ever imagined you would on gear. Your wife won't be happy with you.

[paulster]

Any one know what the pre-89 PTs were matched to the S3801 in an Express?

I'm going to bump this as I'm not sure we've ever seen documented here what the corresponding PT to the Stancor A-3801 OT was in the Express.

[redshark]

I would like to know what Stancor PT was used with the A-3801

[MCK]

I would like to know what Stancor PT was used with the A-3801

Never managed to find out and in the end used a current crop PT along with my A-3801. Would still like to find out one day.

[M Fowler]

The Stancor A-3801 is 6k6 primary and suited for use in the Express and some also have used it in the Liverpool.

[MCK]

Hi Mark, would you happen to know what PT KF may have used in his early A-3801 builds? Thanks

[M Fowler]

Hi Mark, would you happen to know what PT KF may have used in his early A-3801 builds? Thanks

NOS and old audio equipment power transformers from what I've been told.

[MCK]

Thanks. Wonder what they were. Maybe one day we'll find out.