New Build: Ceriatone Replica OTS 50W

[M Fowler]

http://hoffmanamps.com/MyStore/perlshop ... D=!ORDERID!

Doug Hoffman has 5v relays and other amp stuff.

[dwietzel]

Well I have decided to go with the 100 watt version. Ordering more stuff

Guess I need to change the forum name.

[Charlie Wilson]

Then you will be able to use the half power switch.
CW

[stelligan]

More is almost always better....

[dwietzel]

Well finally got all my parts in. The iron lineup will be a ClassicTone PT, and Heyboer OT and Choke. Also went with separate Hammond PT for the relays.

Pics

Iron 1.jpg

Iron 2.jpg

Iron 3.jpg

Looks like the OT will not fit in the opening and I have a questions about that later. I am thinking of going about this build roughly in the following order:

1. Heater wire
2. Relay circuits and transformer for relays

Relays.jpg

3. EQ and Inputs to circuit board
4. Circuit board to Tube section
5. Power circuit next
6. Wire up iron

Questions:

1. Any comments on the build order?
2. The OT hole is not quite large enough. Needs about a 1/8 inch on each side removed to fit. Should I find a CNC shop to try and do this? Any suggestions?

Thanks

[xtian]

2. The OT hole is not quite large enough. Needs about a 1/8 inch on each side removed to fit. Should I find a CNC shop to try and do this? Any suggestions?

It's an aluminum chassis, right? I just use a jigsaw and then clean up with a file to create (or enlarge) transformer cutouts.

[ToneMerc]

2. The OT hole is not quite large enough. Needs about a 1/8 inch on each side removed to fit. Should I find a CNC shop to try and do this? Any suggestions?

Ceriatone, in many cases does not use a PT with an inside end bell. Thus, the chassis cutout is smaller. Personally, I would not cut on the chassis as its much easier just to remove the endbell of the PT.

Years ago I had to do the same thing with one of the early Brownnote Blue Monkey 88 chassis. It had the correct 3x3.75 mounting centers but with an undersized cut out.I heated the laminations perimeter with a hair dryer and then carefully scored the endbell lacquer coating with a razor knife and the endbell raised right up like butter.

TM

[dwietzel]

Thanks for the ideas! Glad you both caught my mistake (should of said PT not OT).

[dwietzel]

Went to Lowe's and bought a set of files (flat, half round and round with handles).
Since it is probably 1/8 inch going to try that route (hmm...pun or not?).

[martin manning]

Can you elevate the PT to get clearance? You should have nuts between the end bell and the chassis, and you could perhaps add more.

[dwietzel]

Well Mike from Marsh amps also suggested removing the Bell on the PT and then it should fit. Looks like that will solve it !

[dwietzel]

Heater wiring in place.

Heater Wiring.jpg

Bell is off of the PT and fits perfectly.

PT No Bell Fits.jpg

Question: The six lug 1/4 jack for FET shown, does anyone know what being "switched" is? Was in the description when I ordered.

FET Input.jpg

[pompeiisneaks]

A switched jack has a third terminal that can be used for various 'on/off' type uses. Basically it is connected to the tip when there is no jack inserted, but when there is, it is disconnected. This allows routing of signals one way, until a jack is inserted into it, and then another way at that point.

Example, dual input jacks usually set the second jack to have the switched connection to ground so the unused jack is grounded when not in use, but when in use creates a slightly different pathway. See Fender standard input Hi/Lo jacks as an example.

Forum member Sluckey has a great explanation of this in his amp scrapbook pdf here: http://sluckeyamps.com/misc/Amp_Scrapbook.pdf

Edit: Should have mentioned page 8 has the Fender Hi/Lo info.

~Phil

[davebolden44]

heater wires are the last thing I put in an amp. to each his own but you are building an obstacle course. good luck with your build.

[davebolden44]

I just completed an ods 100 watt build. I ordered all new jacks because I hate the ones ceriatone uses. I used a switchcraft 14b from mouser for the fet circuit. I drew a picture of the 5 solder lugs on the jack and referenced them to a schematic(not layout) and labeled them 1,2,3,4,5 so to make it idiot proof. If my number 3 lug should hook up to the fet pot via schematic then...well you get the point.