Twin Reverb Reissue to ODS Conversion?

[FUCHSAUDIO]

I do the V-1-B fb switch with 22-Meg on the way to the switch, and 22 and 22 on the switch, so you can do 22 44 66 meg with a 3-way center-off mini...subtle yes, cool very. Worth having if you want a tad more attitude and gnarliness.

[jaysg]

I would do a low plate non-HRM if you want the clean sound to be closest to the Fender clean sound (I did and it is). The HRM amps do require a longer tweak time IMO. On the non-HRM amps I agree with most that the .047 mid cap sounds best for Strats but I like the .01 mid cap on the HRM amps. Buy one of each and season to taste or put on a switch.

Are you talking about the classic tone stack or skyliner?

[Tonegeek]

I would do a low plate non-HRM if you want the clean sound to be closest to the Fender clean sound (I did and it is). The HRM amps do require a longer tweak time IMO. On the non-HRM amps I agree with most that the .047 mid cap sounds best for Strats but I like the .01 mid cap on the HRM amps. Buy one of each and season to taste or put on a switch.

Are you talking about the classic tone stack or skyliner?

Skyliner

[Chris Brown]

OK the plan is coming together

I orderd board and eyelets today. Before I start ordering components I thought I'd make a post to confirm a few things...

From what I've gathered the common 1tube reverb is the one found here: https://tubeamparchive.com/viewtopic.php?t=12440 Is that correct?

For the loop it's basically a dlator without the power section... I'm thinking that I will follow along with what is shown in the layout that talbany posted earlier ( https://tubeamparchive.com/download/file.php?id=14093 )... is this how you would do it?

For the power section... 220 @ 350V for the big ones seems to be what people are doing.... something like what's show here: https://tubeamparchive.com/viewtopic.php?t=11121 ... instead of the hard to find 300uf and also the parallel 10uf etc etc... does this seem right?

To drop the fet input I need to add a 150K resistor to ground after B+5 to keep the load right. Do I understand that correctly?

I plan on skipping the ground / death cap switch... I have read that there are some safe ways to implement that but I've never had a ground switch so I think I can live without one.

I'm definately going to add the mid cap switch... I was thinking a pull switch pot for the mid control. Maybe the nfb switch on the presence control also.

I have not researched the footswitching yet... tonight after the gig maybe. I'm thinking drive, mid and pab.... This amp will be used in a stage context and I know that I often find myself needing a little bit more durring a solo or whatnot so I assume that aside from my guitar's volume control the pab switch is where that will be found.

Aside from the above I plan on following 124. I see that there a lot of satisfied builders of 124 and also it seems like a lot of the common build problems have been worked out and are documented through the search button which is a huge bonus.

I am super excited. Thank's again of all the help. I look forward to your feedback.

[Bob-I]

From what I've gathered the common 1tube reverb is the one found here: https://tubeamparchive.com/viewtopic.php?t=12440 Is that correct?

That's the one

For the loop it's basically a dlator without the power section... I'm thinking that I will follow along with what is shown in the layout that talbany posted earlier ( https://tubeamparchive.com/download/file.php?id=14093 )... is this how you would do it?

Yes, but you'll need to have 2 nodes for the PS. For my amp I took a leg off the screen supply and used 2 22uF with a resistor between them. I don't remember the value of the resistor but I do remember testing a few values.

For the power section... 220 @ 350V for the big ones seems to be what people are doing.... something like what's show here: https://tubeamparchive.com/viewtopic.php?t=11121 ... instead of the hard to find 300uf and also the parallel 10uf etc etc... does this seem right?

2 x 220uF works well. The rest of the nodes should be 2x47uF, not 10uF.

To drop the fet input I need to add a 150K resistor to ground after B+5 to keep the load right. Do I understand that correctly?

Yep

I plan on skipping the ground / death cap switch... I have read that there are some safe ways to implement that but I've never had a ground switch so I think I can live without one.

Yep

I'm definately going to add the mid cap switch... I was thinking a pull switch pot for the mid control. Maybe the nfb switch on the presence control also.

I have not researched the footswitching yet... tonight after the gig maybe. I'm thinking drive, mid and pab.... This amp will be used in a stage context and I know that I often find myself needing a little bit more durring a solo or whatnot so I assume that aside from my guitar's volume control the pab switch is where that will be found.

Aside from the above I plan on following 124. I see that there a lot of satisfied builders of 124 and also it seems like a lot of the common build problems have been worked out and are documented through the search button which is a huge bonus.

I am super excited. Thank's again of all the help. I look forward to your feedback.

Sounds like a plan.

[Tonegeek]

2 x 220uF works well. The rest of the nodes should be 2x47uF, not 10uF.

2x47uF (in series with balancing resistors), if doing the precision PS but you would use a single 20uF (or 22uF) @ 450v for each node (including the parallel 10uF node on the schematic) if using the supply #124 had originally.

Order a few extra caps in the picofarad range for tweaking the volume and master volume treble bleed. The 300pf listed on the schematic for the volume pot is unusable IMHO. 120pf (Fender value) makes more sense. Also don't use that network on the Send/Return but you probably wouldn't since you chose to put the dlator onboard. Get extra values for the supply nodes and the FET simulator (I did not use one at all on my conversion -all my other amps have 150k - 240k). I think I used a 43k dropper off the screen supply node to the node for the dlator recovery triode and 75k off that node to the cathode follower node. That's with an old Twin tranny and the other dropping values as per the schematic. YMMV.
good luck

[Structo]

Yeah, the .001uF bright cap on the D'lator is way too much as well.

If you have to order all your resistors and such.
Be sure to order extra. Like if you only need one or two of a value, order four.
It's very frustration when you screw up a part only to realize that was the only one you had.
Radio Shack is no help nowadays.
I bought a LED there yesterday and I told the sales clerk that I missed the days when they sold nothing but components and ham radio supplies.
I got a blank look in return.

So yeah, take your time when looking up parts. The shipping charges can eat you up if you screw up too much. (don't ask)

Be sure to check the data sheets for all the parts to be sure they are what you need and are the right physical size.
See my Vishay PR01 rant.

You will want to order a few different 2 or 3 watt resistors for your voltage dropping string on the filter board.

Say the layout calls for a 2K, 22K, 2K
I would also get a 1K5, 2K5, 20K, 25K, etc. to give yourself a little wiggle room on the plate voltages.
It is these resistors that you adjust to get the preamp plate voltages you want.

[David Root]

Tom, thanx for those two layouts! They are of general interest to us D-Generates!

[Structo]

You are welcome David.
The bright on clean is really a good mod.
And it doesn't change the appearance of anything.
You just change the Bright switch to a On-Off-On and add a relay.

Thanks to Tony for the layout.

[Chris Brown]

A quick question... is there any reason not to use unclad fr4 perfboard for the recitifier, bias and relay supply boards? I have some laying around that I don't use for fx projects.. this stuff: http://www.mouser.com/ProductDetail/Twi ... scDQ%3D%3D

I assume I can add eyelets and it will be fine but I thought I'd ask for opinions from the community...

Also... though I'd give an update...

Big box from mouser arrived today... still waiting on the eyelet board delivery and tubesandmore shipped today.... looks like everything will be here by the end of the week.

I'm going to start disassembling the twin in the next few days... I'll be sure to snap some photos.

Thanks again everyone!

Best, CB

[Chris Brown]

Just thought I'd drop an update...

All of my parts are stocked now, twin is disassembled, new holes drilled for footswitch jack and fx loop, tag boards and ground lugs bolted to chassis, boards cut and ready to drill for eyelets.

Anyone know a 5pin din jack that is a match for the 3button switch at aes.. the ones I ordered aren't a match ( this one ) .. the holes are all crammed on one side of the jack instead 1 and 5 being past half way ... looks like ( this one ) would work but it's a strange style.

Anyway... that's where I'm at... I'm going to wire the rectifier board, front panel connections and the tube sockets when I get a night off.

Thanks again for all the help!

Warm regards, Chris Brown

[Bob-I]

Anyone know a 5pin din jack that is a match for the 3button switch at aes.. the ones I ordered aren't a match

Personally I'd rewire the AES footswitch. The DIN you ordered is more solid than the AES match. Just get a 592-0511 from DEM and an old MIDI cable and solder away.