Output transformer- 5e3

We (son and I) finally got his kit together and we are pretty pleased and will post pics once I figure out how to do so. But as expected first builds are often full of lessons... my first big lesson is matching speaker ohmage to your OT! We decided to keep the 2 ten inch golden Celestions and redo the OT but I am wondering... are the Mercury transformers a worthy upgrade?

I've never had MM personally but they have a good rep regards the product quality and selection. The common remark is MM are excellent quality but you are paying extra for nice outer garb, like the chrome oil cap syndrome. Thats fine when plenty of expendable cash is around, but now many are hunting for alternates.
Heyboer is a prime component and old school with no gloss or polished paint. The Hammond replacements also are excellent and best $/quality ratio IMO and where I am headed unless I can find a good old thing that I know will work. And Hammond lists their specs so you can know what you have in that part without guessing.

Afaik 5E3 wants 8k primary coil, not the 6.6k sometimes listed for 5E3,6G2-afaik anyway. I'm not a long time expert on this stuff I admit, just sharing what I've come to understand. And the diff in Pri impedence may not matter in reality. But a true 5E3 build attempt with a vintage era low watt'g alnico spkr may well be best with the 8k spec. If I do end up building a 5E3 with my 70ma PT values this detail is to me important in the tone dept.

Tone upgrades are tricky unless you have a definite goal in mind, such as "Now it sounds like this, but I want it to sound more like that". Otherwise how will you know it sounds better than something that never was?

I suggest you talk to an amp expert like Bruce Collins at Mission Amps. He can sell you a Mercury if you decide on that, and he has other stuff that's very good and also cheaper. He sells MM as an option (upcharge, of course) for his 5E3 kit, but his standard OT sounds excellent in my 5E3. I would never pay extra for the MM.

MM's are certainly more expensive. "Upgrade" depends on you, your taste/opinions, the part and it's application, etc.

The OEM style Hammond 5E3 OT's are surprisingly nice sounding for their price. Hammond's other OT's that you can use for 5E3's sound a little tighter and cleaner, but to some tighter and cleaner is an upgrade in their opinion... to purists and tweed police, its sacrilege to use anything other than authentic spec parts.

Its up to you.

... to purists and tweed police, its sacrilege to use anything other than authentic spec parts.

:mrgreen: that's funny!

I just got a MM set FDTP 240-M and a FTDO-59. I will experiment it in one week, at this point my tweed is at dry dock.

MM power transformer looks tiny (in size) comparing with the weber pt which is a lot beefier and heavy. Also, MM does not bring bell ?!

Other thing that you may pay attention is to the voltages. The guys at Mercury swear by the stock specs... 380-0-380 @ secondary!? there's a lot of buzz buzz about this, maybe it's just Internet folklore

Other than that they look great!

the other thing that you may pay attention is to the voltages. The guys at Mercury swear by the stock specs... 380-0-380 @ secondary!? there's a lot of buzz buzz about this, maybe it's just Internet folklore.

My $.02: 380-0-380 in a tweed Deluxe is utterly ridiculous. The resulting plate voltage will put you in a "Can't get there from here" situation.

Reference Deluxe Reverb AB763, you're looking at 330-0-330 which works out to around 420 on the plates (also assuming old school 117 volts at the wall). Just use it as an apples to oranges comparison or wait for the Debate Team to show up with a rebuttal.

Forget the internet buzz, download the tube data sheet and hit the numbers.

My $.02: 380-0-380 in a tweed Deluxe is utterly ridiculous. The resulting plate voltage will put you in a "Can't get there from here" situation.

Reference Deluxe Reverb AB763, you're looking at 330-0-330 which works out to around 420 on the plates (also assuming old school 117 volts at the wall). Just use it as an apples to oranges comparison or wait for the Debate Team to show up with a rebuttal.

Forget the internet buzz, download the tube data sheet and hit the numbers.

I also think that 380-0380 is way to much. The weber pt I had in my amp was 340-0-340 and it was putting out 388v B+. No I imagine what a 380-0-380 would do....

In any case I have figured I like the way my amp reacts wit a B+ around 350v, gives me nice dynamics and a progressive breakup. Above this gets too nasty.

Could it be the MM pt @380v is a no-load voltage? That is my guess.
I have a vintage Chicago Standard that is almost exact spec of the stock 5E3 pt giving 320/0/320v ct @70mA and 6.3x3a, 5vx2a. Gross DC is 360/0/360v ct at no-load. That will drop as soon as the tubes are in the circuit and pulling 50-70mA. So I would guess the MM numbers are at no load...?

While MM takes some criticism for the apparent too-high prices(and I'm too cheap to pay for them too until I have some great old Fender needing a new unit) I think it likely for the price one gets a very excellent quality and integrity in the materials and manufacturing process used in their product. And they probably pay their people a good wage to keep them in employ and not leaving or hating working there. Sort of like buying Alembic,Ric, Suhr and the other still made in America, by USA folks!...that's a good thing for us all as we are beginning to find out:rolleyes: Not sure this is the case but hope it is.

Tube.Tone mentions the small MM size to the Weber. The 5E3/5f1/5F2/6G2 pt is small but is only giving the 70mA output. That Weber I believe is 120mA or even 150. Importantly, as I understand it, the 5E3 is really dependent on the sag of the full current output being used to really tweak the 5Y3 rect and have large v swings=part of the 5E3 character. The 6G2 looks very interesting to me also as a relatively low volts fixed bias 6V6 amp. I am still undecided between these which p/p to build- the 6G2 is tempting.

Not debating the previous posters, just saying it is neccesary to know the full context the spec numbers are presented in and yes many internet misuderstandins derive from missing info's in the big picture.:roll:

HI there,

MM FTDP states 380-0-380 no loaded (not sure what this means).

In a few day I can say in first person what that traslates after all tubes are in place... I will start with NOS rectifier and a 300ohm cathode resistor.

Then I will experiment with a weber cooper cap and see were voltages end up. My experience tells me this rectifier drops B+ in about 50V.

If B+ is too high for my taste I'll try to plug in the different available primary taps.

Talk to you soon.

ps: sure they look good!
http://i98.photobucket.com/albums/l269/88nuno88/P1020999.jpg

No-load 380/0/380 ct refers to just the straight volts measured as AC from the 2ndry. Using the dmm to measure - 1 lead goes to 1 of the red 2ndry wires, the other lead to the red/yellow center tap and nets MM's 380vac-should be close. This is with nothing else involved-just the short lead wires off the component. Of course as soon as that installs into the circuit layout and is rectified it settles to the B+vdc.
Very nice looking chassis and the MM's should give good long term reliability. Looks like you are close to sound! Have fun!

While MM takes some criticism for the apparent too-high prices(and I'm too cheap to pay for them too until I have some great old Fender needing a new unit) I think it likely for the price one gets a very excellent quality and integrity in the materials and manufacturing process used in their product.

Umm... Big Advertising Budget is part of it.

Tube.Tone mentions the small MM size to the Weber. The 5E3/5f1/5F2/6G2 pt is small but is only giving the 70mA output. That Weber I believe is 120mA or even 150. Importantly, as I understand it, the 5E3 is really dependent on the sag of the full current output being used to really tweak the 5Y3 rect and have large v swings=part of the 5E3 character.

You're talking about two different Weber transformers. Weber's Champ transformer is 100ma, Weber's Deluxe transformer is 150ma.

Dave Allen's custom Heyboer "Deluxe" tranny provides a whopping 180ma on the high voltage.

I really really don't want the "character" of my amp to be dependent on an underrated transformer no matter how "vintage correct" that's supposed to be. That may mean my "vintage correct" transformer will be melting its guts out (literally!) while I'm jammin' my pants off (figuratively). I'll take the 150ma from the "vintage incorrect" transformer, thank you very much! There's also 3 amps on the 5 volt winding, this particular combination covers my backside for all sorts of "silly" things I might want to try such as:

Substituting 5881 or 6L6 tubes for the 6V6s.

Swapping rectifiers with tubes that require 3 amps on the filament like the 5U4G which coincidentally works really well with 5881s or 6L6s.

If B+ is too high for my taste I'll try to plug in the different available primary taps.

You don't have that option. Your 5 volt filament winding must be 5 volts, your 6.3 volt filament winding must de 6.3 volts.

Say you jumper your primary to increase the HV secondary 10%. Your 6.3 volt filament will also increase 10%, say .63 volts. It's not good for your tubes and your amp may hummmm...

Jumper the primary to drop the secondary 10%, your filaments drop accordingly. Say we're down at 5.7 volts on the filaments, no big deal. Well... change the filament voltage on a tube tester if you get a chance. Your tubes test as "good" with the correct filament voltage, drop it and they test as marginal or bad. Get it? Drop your filament voltage and your expensive NOS tubes perform like worn out junk.

You don't have that option. Your 5 volt filament widing must be 5 volts, your 6.3 volt filament winding must de 6.3 volts.

Say you jumper your primary to increase the HV secondary 10%. Your 6.3 volt filament will also increase 10%, say .63 volts. It's not good for your tubes and your amp may hummmm...

Jumper the primary to drop the secondary 10%, your filaments drop accordingly. Say we're down at 5.7 volts on the filaments, no big deal. Well... change the filament voltage on a tube tester if you get a chance. Your tubes test as "good" with the correct filament voltage, drop it and they test as marginal or bad. Get it? Drop your filament voltage and your expensive NOS tubes perform like worn out junk.

Exactly, you're totally correct!
I have jumpered the220vac to the 240V on a MM FTDP tap as an experiment. The B+ was fine, ended up around 360v. Although all other voltages changed at the same ratio, the rca 6v6 were sounding like crap and the rectifier tube was running cold.

As an alternative I have connect the correct primary tap 220v and I replaced the nos 5Y3GT for a Copper Cap WY3GT. This is what I got:

5Y3:
Pin 3=372V
Pin 8=375V
6V6:
Pin 3=365V
Pin 4=332V
Pin 8=20V
Pin 3-4=347V
Cathode Current=36Ma

I think this is fine and I happy with the sound.
Thanks for your thoughts!!

Umm... Big Advertising Budget is part of it.



You're talking about two different Weber transformers. Weber's Champ transformer is 100ma, Weber's Deluxe transformer is 150ma.

Dave Allen's custom Heyboer "Deluxe" tranny provides a whopping 180ma on the high voltage.

I really really don't want the "character" of my amp to be dependent on an underrated transformer no matter how "vintage correct" that's supposed to be. That may mean my "vintage correct" transformer will be melting its guts out (literally!) while I'm jammin' my pants off (figuratively). I'll take the 150ma from the "vintage incorrect" transformer, thank you very much! There's also 3 amps on the 5 volt winding, this particular combination covers my backside for all sorts of "silly" things I might want to try such as:

Substituting 5881 or 6L6 tubes for the 6V6s.

Swapping rectifiers with tubes that require 3 amps on the filament like the 5U4G which coincidentally works really well with 5881s or 6L6s.



You don't have that option. Your 5 volt filament winding must be 5 volts, your 6.3 volt filament winding must de 6.3 volts.

Say you jumper your primary to increase the HV secondary 10%. Your 6.3 volt filament will also increase 10%, say .63 volts. It's not good for your tubes and your amp may hummmm...

Jumper the primary to drop the secondary 10%, your filaments drop accordingly. Say we're down at 5.7 volts on the filaments, no big deal. Well... change the filament voltage on a tube tester if you get a chance. Your tubes test as "good" with the correct filament voltage, drop it and they test as marginal or bad. Get it? Drop your filament voltage and your expensive NOS tubes perform like worn out junk.

Great Post-Thanks for that. Not trying to debate merits and pro's and con's. just in spirit of sharing and FUN! I stand by my OPINION that the small PT has its place in the rebuild market. A stage amp run full throttle-yeah your right regards its no-extra capacity-of course, But it was never designed with that intent- as I understand it was somewhat a fluke and to fill a market gap for Fender. Anyway you know more than I do, I'm just a little learner out here sheepishly attempting to participate. Back to my cubicle, I mean shop, or boat, or sunshine, or whatever...Have fun! Its Fun! And no cost. Be Well mates:grin:
PS- the big 180mA Heyboer you mention is not intended for 5E3 afaik....