favorite X-formers for Dumble circuits...

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Paul-in-KC
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favorite X-formers for Dumble circuits...

Post by Paul-in-KC »

All,

I have decided to build a Dumble circuit. I purchased a chassis and board set from Amplified Nation, so just need to pick a circuit and source the parts.

I am leaning toward a 2nd or 3rd generation 50W ODS.

I have started researching the transformers a little and was wondering which manufacturers are favored by the experienced Dumble builders. Fender, Mercury Magnetics, Heyboer, Hammond, Classic Tone (Magnetic Components)???

I have used Mercury Magnetics in the Marshall circuits that I have built - and been quite happy with those. Used Heyboer in a Trainwreck Express - and super happy with it.

Do the Dumble circuits "like" some better than others? Or do you just get a slightly different flavor of awesome? :D

No doubt this question will be followed up with numerous others as I make my way through the process.

Thanks in advance for sharing your hard earned knowledge and opinions.

Kind Regards,
-Paul
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xtian
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Re: favorite X-formers for Dumble circuits...

Post by xtian »

I have been perfectly happy with the lower cost options, which include Fender OEM (100 watt Twin iron, e.g.), ClassicTone, and Edcor. Heyboer has a good rep but I've never used. MM just seems overpriced, and I've avoided them for that reason alone.
I build and repair tube amps. http://amps.monkeymatic.com
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M Fowler
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Re: favorite X-formers for Dumble circuits...

Post by M Fowler »

Like John Suhr and Dave Friedman said in a video on Tone Talk there is no reason not to use Heyboer transformers rather then Mercury but I always use Magnetic Components because they are priced well and high quality in performance. Magnetic Components may not look as well polished as some other brands but they are a fine choice.

Use whatever you want, the main difference in amps is the output transformer selected but this is a subjective decision on your part.

Mark
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dreric
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Re: favorite X-formers for Dumble circuits...

Post by dreric »

50 Watts go with Bassman iron
100 Watts go with Twin reverb iron

IMO, you have to drink special cool-aid to justify the price of Mercury, and their web page is technically useless.

Magnetic Components webpage is a great resource and their products sound great.
Heyboer makes a great product also.

I've never seen anyone rave about Hammond OTs.
Eric
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norburybrook
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Re: favorite X-formers for Dumble circuits...

Post by norburybrook »

I'm in Europe( that place across the big stretch of water :D ) so I've used either Hammond or more recently I've been having transformers made by InMadOut in Italy, wonderful things they are :D first set I powered up I thought were broken because there was no hum at all...ZERO.. in a quiet studio. The hammond transformers I'd used I the past always hummed slightly.

My main reason at first was to get a power transformer that had an extra separate 6v secondary tap for the relays so I didn't have to use a separate transformer. I discovered though that they sound amazing too, so I've kept using them for all my builds.



Marcus
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norburybrook
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Re: favorite X-formers for Dumble circuits...

Post by norburybrook »

dreric wrote: Wed Dec 13, 2017 4:02 am

I've never seen anyone rave about Hammond OTs.

My first #102 build has Hammond tramsformers and I sold it to eric Claptons guitarist who thinks it's the best sounding amp he's ever heard :D



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Bombacaototal
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Re: favorite X-formers for Dumble circuits...

Post by Bombacaototal »

dreric wrote: Wed Dec 13, 2017 4:02 am 50 Watts go with Bassman iron
100 Watts go with Twin reverb iron

IMO, you have to drink special cool-aid to justify the price of Mercury, and their web page is technically useless.

Magnetic Components webpage is a great resource and their products sound great.
Heyboer makes a great product also.

I've never seen anyone rave about Hammond OTs.
Just a question, If using a Bassman OT (4.2K primary) and a Bandmaster PT for about 52W of power with 2 x 6L6 what you suggest to match the impedance. As far as I recall on a push-pull AB the 6L6GC are 6.6K with 360V at plate or 5.6K with 450V.
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norburybrook
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Re: favorite X-formers for Dumble circuits...

Post by norburybrook »

I wouldn't worry about it. IMH experience OT are quite robust in their ability to manage impedance mismatching. My 40 year old Bandmaster has survived well with a 4 ohm output driving 8-16 ohm speakers no problem.



Just my impression so don't take this as gospel truth :D


Marcus
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martin manning
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Re: favorite X-formers for Dumble circuits...

Post by martin manning »

HAD used Fender transformers, even recycled ones, which is another option. Pick up a Twin Reverb/Showman set from a reputable manufacturer and you will be fine. My ODS has a mixed marriage of a Hammond PT and a Heyboer OT from Mojotone.
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norburybrook
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Re: favorite X-formers for Dumble circuits...

Post by norburybrook »

don't forget 80's Peavey transformers. HAD used Peavey transformers on a couple of ODS builds, I think #170 is Peavey.

I've bought a couple of old peavey combo's for the transformers and they've made great Dumble amps.

you'll have to use a FWBR to get the voltages but it's an easy thing to do as the rectifier board on the ODS is large and it's easy to modify for this. My JM/WOnderland is built with peavey Iron and is a sweet sounding amp.



Marcus
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Re: favorite X-formers for Dumble circuits...

Post by Bombacaototal »

norburybrook wrote: Wed Dec 13, 2017 12:09 pm I wouldn't worry about it. IMH experience OT are quite robust in their ability to manage impedance mismatching. My 40 year old Bandmaster has survived well with a 4 ohm output driving 8-16 ohm speakers no problem.



Just my impression so don't take this as gospel truth :D


Marcus
Got it! So, a Bassman OT driving a matched impedance speaker cabinet (i.e. 4 Ohm tap into a 4 Ohm cabinet) with a pair of 6L6GC should be just fine then...Or would mismatching (ie 4Ohm tap into 8Ohm cabinet) creating a 8.4ohm primary be better?
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Paul-in-KC
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Re: favorite X-formers for Dumble circuits...

Post by Paul-in-KC »

M Fowler wrote: Wed Dec 13, 2017 3:05 am Like John Suhr and Dave Friedman said in a video on Tone Talk there is no reason not to use Heyboer transformers rather then Mercury but I always use Magnetic Components because they are priced well and high quality in performance. Magnetic Components may not look as well polished as some other brands but they are a fine choice...

Mark
Thanks Mark (et al.)!

I decided to go with the Classic-Tone parts.

-Paul
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Re: favorite X-formers for Dumble circuits...

Post by Travis_HY »

M Fowler wrote: Wed Dec 13, 2017 3:05 am Like John Suhr and Dave Friedman said in a video on Tone Talk there is no reason not to use Heyboer transformers rather then Mercury but I always use Magnetic Components because they are priced well and high quality in performance. Magnetic Components may not look as well polished as some other brands but they are a fine choice.

Use whatever you want, the main difference in amps is the output transformer selected but this is a subjective decision on your part.

Mark
I have to share that Dave has used Hammond and Classictone trannys in the past-he just gets a better deal on quantities from Heyboer. It's all about quantity costs.
"Genius manifests itself. You got a hammer. You either build a Cathedral or you build a shithouse." - Carl Schroeder
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didit
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Re: favorite X-formers for Dumble circuits...

Post by didit »

No doubts that Hammond Twin set would be fine, so there's a box full by the bench. Pleased to have Marcus' affirmation of that choice.

Best .. Ian
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67plexi
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Re: favorite X-formers for Dumble circuits...

Post by 67plexi »

Dumble did use Magic Parts Thordarsen-Meissner transformers. I got a 28 year old NOS twin set for my 102 build what a difference :D
I started out with a stock 1971 twin set.
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