5E3 Clone Pre-Build Questions

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Hiya Folks,

I just wanted to check a few things before this build.

Regarding transformers, what B+ should I be looking at? I've measured the UK mains as high as 242v so could use the 240v tap on the Mercury Magnetics FTDP/240-M (taps for 220,230 and 240) to give their suggested stock 380-0-380 unloaded. But isn't 380 a bit high? It doesn't give voltages on the Fender drawings I'm working to.

Also, they do a Fatstack version, the only difference being the extra iron. Is there anything to gain from this or is it just hype?

The MM OT offerings state they handle 50% more power. Does this just mean they will run at higher B+ for different tubes for example?

Finally, if at any stage I decide I want to tighten up the bass, is there any decisions to be made regarding the PT and OT right from the off that will help with that?

Just so you know, I want a CLONE first and foremost and it might well stay that way but being able to tweek things (and have the best trannys in place to do so) would be good.

Thanks.

[MWJB]

380-0-380VAC unloaded isn't really very useful information as working voltages are always measured loaded with tubes & subsequent current draw. That 380 would drop with tubes installed.

You want it both ways (sorry if I sound like a killjoy), a "clone" would really be built on adequate transformers (2A heater current capacity, 100mA B+ current capacity)...if you want extra heater current capacity & beefier OT, then it's not really a clone, but an upgrade (no harm in that...it's what I'd do).

The OTs are what MM claim have higher W rating. If their PT gave significantly higher B+ voltage (required for more power) it would burn up tubes in the stock circuit. To give you a guideline - a Mojo/Hyboer 5E3 PT will give 380-385vdc with the stock circuit & a NOS 5Y3 (avoid the Russian Sovtek/Reflector), some mfrs offer PTs that will deliver around 350-370vdc at the plates for "classic" 5E3 tone.

If you want to tighten bass then I'd probably recommend you start with a 330ohm 10W cathode resistor, this will allow for a slight voltage hike if you fit a tighter rectifier like a 5V4. I'd also go with 40-50uf at the main B+ filter cap and a 100uf/100v 6V6 cathode bypass cap.

If you want to perhaps upgrade to/experiment with 6L6s in the future I'd suggest a TAD/Mojotone BF Deluxe PT & OT (probably Hyboer), a bit more current handling & lower B+, good value. The OT will be happy enough with the mismatch in impedances with
6L6 fitted.

If a tighter response & low end is what you might be after I'd also consider a fixed-bias/cathode-bias switch.

[ad30]

OK, MWJB. If I go for the adequate vintage trannys as you describe, can I do the majority of the bass response correction with the other mods you suggested? I have no interest in 6L6's by the way.

What I don't really understand is what exactly the upgraded transformers with extended current handling will do. Does it just mean you can ask more of the OT and PT (by making more demand via the tubes/circuit) and it will cope?

And is the extra iron on Fatstacks a farce?

[MWJB]

"OK, MWJB. If I go for the adequate vintage trannys as you describe, can I do the majority of the bass response correction with the other mods you suggested? I have no interest in 6L6's by the way." 5E3 are reknowned for being overly bassy if anything (especially with humbuckers), but if you want that low end to reproduce in a tight note, with better transient response, then bigger transformers (& maybe even fixed bias) are a good idea. However, stock style trannies with a 5V4 rectifier, bigger main filter & 6V6 cathode bypass caps will significantly improve the amp over the original parts (5Y3 & 20uf main filter contribute to the amp mushing out), the amp should happily keep up with a sympathetic drummer using sticks.

"What I don't really understand is what exactly the upgraded transformers with extended current handling will do. Does it just mean you can ask more of the OT and PT (by making more demand via the tubes/circuit) and it will cope?" An overrated PT will suffer less voltage drop under load and have better transient response & dynamics, even if the B+ remains the same at idle. However, the difference between 5E3 & BF Deluxe transformers is not that huge & it could be argued that part of the Tweed Fender charm is amps built with adequate transformers rather than overrated transformers. An overrated OT may give a shade more clean headroom in some amps...debatable whether you will get a significant advantage in a 5E3 circuit...and take longer to burn up if fed high idle currents. In a 5E3 circuit 40mA per tube is about as high as you want to go, so that point is pretty well moot...adequate is adequate. Note that I have seen late model 5E(F?)3 that appeared to be fitted with a Schumacker tolex Deluxe OT as stock...it sounded like regular 5E3.

"And is the extra iron on Fatstacks a farce?" You'd have to build 2 otherwise identical amps & have one with the MM and the other with stock to really evaluate that.

[fyl]

Regarding transformers, what B+ should I be looking at?

Around 330V loaded.

But isn't 380 a bit high?

The MercMag shows quite high losses and goes down to around 330V when fully loaded. This isn't a defect : they've tried to emulate vintage iron which showed similar losses.

Also, they do a Fatstack version, the only difference being the extra iron. Is there anything to gain from this or is it just hype?

IMO not worth the added cost in a 5E3 build - FatStack iron can be a plus in a BF repro, but not in a tweed.

Finally, if at any stage I decide I want to tighten up the bass, is there any decisions to be made regarding the PT and OT right from the off that will help with that?

Iron plays a big part in the voicing but some well chosen components are very effective - for instance using 22n/47n instead of 100n coupling caps can work wonders.

[ad30]

Cheers. That has sort of sunk in though I think in the long run, I'd be better off trying for a complete clone first and then building a second along side to modify. Kind of experience first hand what the mods do.

I've been obsessed with Blackfaces for a while but here's what sparked my interest in Tweed tones. He's a great player too. If I can get either amp to sound like that I'd be happy.

[ame="http://www.youtube.com/watch?v=3X1AOlkabwo"]YouTube- Tungsten Amp Crema Wheat Tweed Deluxe guitarist Greg V. with Fender Nocaster[/ame]

[Bruce / Mission Amps]

Cheers. That has sort of sunk in though I think in the long run, I'd be better off trying for a complete clone first and then building a second along side to modify. Kind of experience first hand what the mods do.

I've been obsessed with Blackfaces for a while but here's what sparked my interest in Tweed tones. He's a great player too. If I can get either amp to sound like that I'd be happy.

YouTube- Tungsten Amp Crema Wheat Tweed Deluxe guitarist Greg V. with Fender Nocaster

Adam, from Tungsten Amps, is one of only a very, VERY VERY few builders that has a Mission Amps "full disclosure" license from me to use all my tweed Deluxe and harp amp mods.
Some of which have been discussed at great length here on the M.E.F., but not so much as to step on his toes.
Also, Adam's 12" AlNiCo speaker is a custom made one that sounds fabulous in tweed amps like the 5E3.

The power tranny rating of 380vac is with the thing supply it's rated current too.
If it is not loaded down by that current, there is a good chance it will actually deliver a higher B+.
The original tweed Deluxe PT was only a 90ma - 100ma PT. The black face Deluxe Reverb PT is about 120ma.... all most all the Deluxe Reverb clone PTs out there now are actually based on the TMI copy of a silver face Deluxe Reverb which is the largest of all the Deluxe series PTs.
I've used many of them in 25 watt 6L6 amps.
The OT is the question though... most of the clones are 15 watt OTs and some are 20 watters, none of them are as large as the OTs found in a 6L6 tweed amp which really needs to be around 25-30 watts.

[ad30]

So because the MM 'Tone Clone - Original Design' OT is rated to handle up to 50% more power, it isn't actually a clone? Or will it sound the same and not use the extra 50% when connected to a 5E3 that is otherwise completely vintage?

[MWJB]

The term "Clone" is overused & misunderstood. MM OTs are wound on plastic bobbins not paper, to handle more power they must have better current handling & thicker wire in the primary windings, therefore less DCR - so they are different in a few respects. "Tone clone" is as much of a catchy moniker in this case. Though that's not necessarily a reason not to buy one...plenty of original 5E3s no longer have their original OT because it burned up (just like my mate's '57 Deluxe OT did after a few weeks of use)!

You want an OT that mates 8.5K:8ohms, plenty of 5E3 got tolex Princeton OTs as replacements, the MM may well outlast them, Bruce can no doubt point you towards his favoured 5E3 OT...as can anyone who builds a lot of them. Note that several builders of note, either have their own proprietry transformers made, or their specs realised by a recognised winder.

When most folks use the term "clone", they really mean an identical facsimile of the original article (cloned animals do not necessarily look, or behave, like the animal they were cloned from), but what qualifies as a clone varies from person to person...different brands of caps, resistors, speaker etc are inevitable & still seems to qualify in most folks book. You probably don't want a Jensen speaker, rated at less than the amp can actually deliver under full drive, in your amp.

All the reproduction 5E3s that I have seen do not "clone" the original amp in EVERY way...most folks upgrade various aspects, parts & layout...how good the final amp will sound is down to how well it is executed, in many cases that will mean changing a few things away from the way that Fender did it. Fender 5e3 are great amps, but as a small scale builder you don't work under the budget & time constraints of a mass production factory - copy the ethos but not the shortcuts, limitations & mistakes.

My advice would be to build the amp as you feel is most fitting...OTs only have 5 wires in a 5E3 and can be changed within an hour of turning the amp off...if you feel you may want to revise your choice at a later date.

[ad30]

MW, what can I say. Impeccable advice again. It must pretty clear cut with all that knowledge to decide what you want from a build and just do it. I don't mind experimenting, spending money and learning to get there. My problem is I'm impatient.

I know what you're saying. Most fitting to me but stick to the ethos.

P.S. You couldn't list what you consider the shortcuts, limitations and mistakes could you?

[Chuck H]

Ok... No one has said it outright yet. Apparently Bruce has too much class to make a direct pitch on the forum so I'll say it. Buy your kit from Bruce / Mission amps. Bruce has already posted, knows the amp your impressed with is an "improved" 5E3 design that puts out a little more power with tighter bass, he's built, modded, and redesigned the 5E3 circuit to the N'th degree and even knows that bit about the proprietary speaker in the "clone" your boy was playing through in the YouTube video. Call Bruce, tell him what you want and he'll take care of you. Then all you have to do is build it and play it.

Let me qualify that I don't know what the added expense of shipping to the UK is for a Mission kit. But it would be WHAT YOU WANT. and that's worth a lot.

Chuck

[Bruce / Mission Amps]

Deluxe Kits

Yup... I hate mixing business with pleasure here.

Shipping to Europe has become a bear lately... I don't know why exactly but the costs have risen way over what the exchange rates are.
I recently contracted my transformer company to send me some Euro power trannys (220v-240v) in a big enough quantity that I won't have to add a transformer surcharge.

However, the MOJO Musical Supply guys are good friends of mine and the MOJO, 5E3 Deluxe kit is distributed by the Tube Amp Doctor in Europe across the channel and over the woods in Germany.
It is a very good amp kit with TAD tubes (good tubes but probably Chinese) high quality supporting parts, really good USA made, paper wound transformers and a made in the USA, chrome plated, mild steel chassis.
I think the kit is only second to mine, if I might be so bold as to say so.
It might be reasonable to find out what that kit would cost.

Amp-Kit Tweed Deluxe Style 5E3 Röhren, AMP Kits und Lautsprecher - Tube Amp Doctor

[Mandopicker]

Good advice Bruce!

[MWJB]

...what Bruce & Chuck say.

[MacLoud]

Mojo kits are sold here in the UK by Allparts.
Allparts guitar spares and parts
Good prices compared to TAD and complete with speakers.
Always good service from Andy and his team.

Delta MacLoud