#124 started

[martin manning]

I think you might have to try it both ways to see which is your preference. There is no precedent for 50W low-plate classic, is there? The 100W layout shows 150uF, so the options are reducing by 27% or 66%...

[norburybrook]

Ok, managed to get a good day in today. I'm going to swap out the two 220uf' for 100's and see how I like it. I can always pop them back in if I prefer more filtering.


I've still no actual plan regarding building these ODS amps. I just sort of start and play it by ear...I've usually forgotten the corners I've painted myself into on previous builds so sometimes end up with the same predicaments.

the deep switch was VERY fiddly with such a small space and so many components!!

I decided not to solder the shields to the back of the pots this time, I thought it was better for the pots not to have a lot of heat going to them. I soldered the shields to the bus bar, achieves the same thing with potentially less damage to the pots.

anyway..not pretty but hopefully functional I'm not really sure how some of you guys manage to make such beautiful amps, I always set of with the intention of making it look great but it seems to go out of the window pretty quickly.


Marcus

[talbany]

I'm not really sure how some of you guys manage to make such beautiful amps, I always set of with the intention of making it look great but it seems to go out of the window pretty quickly.

A few quick ideas on this one
Try to study as many pics of the insides of as many Dumble amps as you can find here!!..Dumble definitely has a style and technique he has developed (circuit constants)..Print a few out pics layouts and keep them by the bench as you build (especially the tone stack switches on front panel).
On the 124 layout I did I tried to run most of the wires the same as Dumble did (even tried to match color ) so that's not a bad guide either!
Also pay close attention to how he runs the wires to the pre-tube sockets
The Dumble layout and lead dress is IMO a rather important part of what makes a Dumble a Dumble, attention to detail and all these little things can effect the tone and add up and can certainly effect reliability especially if your a road warrior!!..NOTHING worse than hearing your s#!t going down in the middle of a solo.. Take your time and wrap each connection!!!
btw..No problem shielding to the buss bar!..I usually shrink wrap the shield on the way..looks better IMO!
Above all enjoy the process!!

Good Luck!

Tony

[jelle]

Hi Tony...you are back!!!

[norburybrook]

Tony, the pictures I have of the real Dumble amps look a complete mess compared to amps I see built on here these days

I have shrink wrapped all the screens on the shielded cable I even added shrink wrap to the bright cap leads as done by HAD from the pics I have.

I haven't wrapped all my connections!! That's something I'll start doing, thank you for the tip.I was thinking about replacing components in the future and wrapping them would make removal more difficult, another lesson learned! I do glue my power caps down as an extra precaution against vibration.

I always follow the wiring to the pre amp valves etc as I'm aware lead dress is important. Also it's easy to see

Looking at some pics again it seems the wiring from the relays to the various pots etc generally goes over the top, I've wired mine underneath, any reason to change that now?...obviously now's the time to do it if it's better


I'm aware though from playing over 10 different clones between myself and my friend, that an amp that looks like a dogs dinner can sound superb, and vice versa, a beautiful amp internally can sometime not sound great.

my old Fender Bandmaster reverb is a rats nest inside but it's whisper quiet and sounds great!!


Glad you're back Tony, between you and Martin M we have an incredible resource, so thank you once again.


Marcus

[talbany]

Hi Tony...you are back!!!

Hi back!..Brother Jelle!..Good to see some old friends still hangin at the garage I've been teaching and playin and traveling and not home as much now so my fun internet time is short but want and will try to check in as often as possible if I can help!!..Keep building those great amps of yours

Tony

Tony, the pictures I have of the real Dumble amps look a complete mess compared to amps I see built on here these days Very Happy

I have shrink wrapped all the screens on the shielded cable Very Happy I even added shrink wrap to the bright cap leads as done by HAD from the pics I have.

I haven't wrapped all my connections!! That's something I'll start doing, thank you for the tip.I was thinking about replacing components in the future and wrapping them would make removal more difficult, another lesson learned! I do glue my power caps down as an extra precaution against vibration.

I always follow the wiring to the pre amp valves etc as I'm aware lead dress is important. Also it's easy to see Very Happy

Looking at some pics again it seems the wiring from the relays to the various pots etc generally goes over the top, I've wired mine underneath, any reason to change that now?...obviously now's the time to do it if it's better


I'm aware though from playing over 10 different clones between myself and my friend, that an amp that looks like a dogs dinner can sound superb, and vice versa, a beautiful amp internally can sometime not sound great.

my old Fender Bandmaster reverb is a rats nest inside but it's whisper quiet and sounds great!!


Glad you're back Tony, between you and Martin M we have an incredible resource, so thank you once again.

Marcus
Sounds like you have it under control..Good luck with the build and let me know if I can help further.

Thanks for the shout out!..Will try to keep up with Martin!

Tony

[amplifiednation]

Tony!!!!

[norburybrook]

not much progress I'm afraid been busy in the studio with a new artists and then a week of gigs.

Transformers have arrived though.....however I didn't read the sizes and the power transformer is too small for the holes in the chassis....bugger......going to have to make up some brackets.....I made the presumption when it said 'Twin' it would be a standard 'twin' mounting.....NO!



Marcus

[martin manning]

Bummer. Or bugger. This was discussed once before: https://tubeamparchive.com/viewtopic.ph ... 455#359455

[norburybrook]

ah, yes I can see now....never mind ..another lesson learned

I'll put a couple strips of alloy across the edge of the hole to mount the transformer. If I paint it black you'll never notice.


A little aside. I used my #102 the other day for bass.....sounded great, really crisp clear sound and the tone controls worked nicely too. Used it through the dumble 1x12 oval backed cab with a celestion G12-80



M

[norburybrook]

well I managed to get my Xmas chores done today and found time to make a bracket from some sheet ally from an old chassis, hence the myriad of spurious holes.

It's actually very easy to work with I found. I made a rough template from card to make sure everything fitted then cut it out from the ally sheet.

painted it to match the chassis as best I could with a brush!!!

should do fine and I'm sure the uneven edges will not show once mounted.



Anyway that's it now until the new year.

merry Christmas and happy new year to everyone here on TAG


TBC in 2017


Marcus

[dorrisant]

Looks fine... besides, if it sounds the way I think it will no one will ever question your method of mounting the TX.

Happy holidays to you too!!

[norburybrook]

home from Christmas break. Decided I'd missed the smell of lead solder and flux so got a couple of hours in today. Decided to use the 4-8-16 OT switch after all.


Flying to Glasgow tomorrow for a gig so Happy New Year to everyone............................TBC


Marcus

[Bob S]

Your build will sound killer Marcus.
Some of the best in the business offering tips & advice - we all benefit from this.
Happy New Year - Glasgow is a fun city - I imagine it's a blast at New Year.
Have fun & be safe.

[erwin_ve]

Marcus, you can run the wires to the master pot unshielded. Just run them parralel with the presence wiring.
Happy Newyear!
Erwin