Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Tyrannocaster on May 19, 2012, 04:14:44 pm

Title: 5E9 Tremolux Tremolo question
Post by: Tyrannocaster on May 19, 2012, 04:14:44 pm
This is (I hope) a simple question: can the tremolo circuit from the 5E9A Tremolux be ported over to other similar amps? It is different from a lot of other Fender trems in that it modulates the PI and not the power amp bias. I am planning to build a 5D3 Deluxe (yes, a 5D3, not a 5E3) and as I own an actual '55 5D3 I have the original here to compare with. I have had this amp for decades and it is the coolest amp I've ever owned, but I have always wished it had trem. So when I noticed that the 5E9A Tremolux is nearly identical to my 5D3 (aside from the tremolo circuit and some coupling cap values, the main difference is the PI, which is slightly different) I started dreaming about a tweed Deluxe with Tremolo. Yes, I could just build a Tremolux, but I LOVE this 5D3 and I'm going to clone it to the extent that I can. That means going through and measuring everything and using the current values rather than what the schematic calls for; when I was doing studio work in LA I used to get session calls because of this amp, which should tell you something about why I like it so much. I like 5E3s but so far I haven't heard one that sounds as good as this old amp does.

I've built several amps (nine, if memory serves) from scratch so I'm not a complete newbie at this, but it has been some time since the last one and I'm having to get back up to speed. Any help would be greatly appreciated.

Thanks!
Title: Re: 5E9 Tremolux Tremolo question
Post by: tubeswell on May 19, 2012, 07:39:08 pm
You might have to make some changes (to - say -  the LFO feedback resistor for example - seeing as how the paraphase PIs are slightly different in both amps) but the general principle of putting a 5E9A trem in a 5D3 should work.
Title: Re: 5E9 Tremolux Tremolo question
Post by: Tyrannocaster on May 19, 2012, 09:09:48 pm
Thanks; that was what I was hoping. I figured it wouldn't be a total copy and paste and I'm sure something will pop up but it did seem like it should be a possibility. I don't know much about tremolo circuits (I've only built two amps with functioning trems, neither like this one) so I need all the advice I can get!
Title: Re: 5E9 Tremolux Tremolo question
Post by: HotBluePlates on May 19, 2012, 10:38:59 pm
Simple answer:

The 5E9 Tremolux is a 5D3 Deluxe, but with the added tremolo (plus a slightly bigger cabinet). So, just build the 5E9 Tremolux.

I used to own a '55 Tremolux, and wish I'd never sold it.
Title: Re: 5E9 Tremolux Tremolo question
Post by: Tyrannocaster on May 20, 2012, 06:47:15 am
Quote from: HotBluePlates on May 19, 2012, 10:38:59 pm
Simple answer:

The 5E9 Tremolux is a 5D3 Deluxe, but with the added tremolo (plus a slightly bigger cabinet). So, just build the 5E9 Tremolux.


Not quite true. The 5E9 is a 5C3 Deluxe and they have different phase inverters, although they are similar. That's why I was worried, understanding as little about tremolos circuits as I do. I do know they can be very finicky, as not all of mine have worked.

Additionally, since I'm going to clone my 5D3 and it has values that have drifted over the years (or maybe were off to begin with), I want to stay with that design. It's one of those amps that, like certain old Fender guitars, had everything go right and ended up being exceptional. Modern amps and guitars are made much more consistently and there are fewer lemons now (and the average guitar is MUCH better than it was 40 years ago) but the rare ones where everything turned out better than average don't happen so often now, either.

Of course, I can't clone everything perfectly on my budget, the OT in particular. However, six or severnyears ago I did this with the 5D3 using an old Thordarson PA system and the result sounded remarkably close to the 5D3. I'm hoping for that result again. I ended up rebuilding the Thordarson into something else (after all, I had the 5D3, right?) but nowdays the old Deluxe is worth so much money I'm kind of paranoid about using it in public and taking it out. I'd much rather take something replaceable...and with tremolo!
Title: Re: 5E9 Tremolux Tremolo question
Post by: sluckey on May 20, 2012, 08:36:27 am
Quote
Not quite true. The 5E9 is a 5C3 Deluxe
The 5E9A looks nothing like a 5C3. Three huge differences are...
1. 5C3 uses all octal tubes. 5E9A uses octals and 9 pin (just like the 5D3).
2. 5C3 preamp is grid leak biased. 5E9A preamp is cathode biased (just like the 5D3).
3. 5C3 has a NFB loop. 5E9 does not (just like the 5D3).

There are other smaller differences too but that's enough to say they are two different amps. I agree with HBP. The 5E9A is much closer to the 5D3. If you build the 5D3 straight up, then add the 5E9A trem circuit adapting it to the 5D3 PI, you will essentially have a 5E9A with  a few minor component differences.

You should have no problems adapting the 5E9A trem to the 5D3 circuit.
Title: Re: 5E9 Tremolux Tremolo question
Post by: Tyrannocaster on May 20, 2012, 09:48:57 am
Quote from: sluckey on May 20, 2012, 08:36:27 am
Quote
Not quite true. The 5E9 is a 5C3 Deluxe
The 5E9A looks nothing like a 5C3. Three huge differences are...
1. 5C3 uses all octal tubes. 5E9A uses octals and 9 pin (just like the 5D3).
2. 5C3 preamp is grid leak biased. 5E9A preamp is cathode biased (just like the 5D3).
3. 5C3 has a NFB loop. 5E9 does not (just like the 5D3).

There are other smaller differences too but that's enough to say they are two different amps. I agree with HBP. The 5E9A is much closer to the 5D3. If you build the 5D3 straight up, then add the 5E9A trem circuit adapting it to the 5D3 PI, you will essentially have a 5E9A with  a few minor component differences.

You should have no problems adapting the 5E9A trem to the 5D3 circuit.


Thanks. When I referred to their similarities I was talking about the power amp, not the preamp. I should have made that clear. The tremolo doesn't affect the preamp circuitry. And that said, the 5D3 sounds a lot better than the 5C3, at least those that I have heard. But I'm not a big fan of octal preamp tubes, although some guys are.

Getting the parts together as I speak. :)
Title: Re: 5E9 Tremolux Tremolo question
Post by: HotBluePlates on May 20, 2012, 10:25:42 am
Quote from: Tyrannocaster on May 20, 2012, 06:47:15 am
Quote from: HotBluePlates on May 19, 2012, 10:38:59 pm
Simple answer:

The 5E9 Tremolux is a 5D3 Deluxe, but with the added tremolo (plus a slightly bigger cabinet). So, just build the 5E9 Tremolux.


Not quite true. The 5E9 is a 5C3 Deluxe and they have different phase inverters, although they are similar. That's why I was worried, understanding as little about tremolos circuits as I do. I do know they can be very finicky, as not all of mine have worked.

Additionally, since I'm going to clone my 5D3 and it has values that have drifted over the years (or maybe were off to begin with), I want to stay with that design.

Sorry, I should have looked over the schematics again, and explained a bit more.

Fender made a "Tremolo"-equipped "Deluxe", and the name was shortened down to "Tremolux". The 5E9A layout shows 4 input jacks, but my '55 was a 5E9 (you'll never find a schematic or layout for those, for some unknown reason); it had the 3 input jacks like a 5C3. The only other significant difference was the tremolo on/off switch was mounted on the Depth pot (where it makes sense), rather than the Speed pot.

Anyway, what I'm saying is build the Tremolux. You want to copy parts that have drifted, so copy the drift to corresponding parts in the Tremolux.

I don't know what problems might arise from using the self-balacing paraphase found in the 5D3 over using the older-style paraphase found in the Tremolux and 5C3. I'd suggest duplicating whatever drift you think is essential to your sound from your 5D3 phase inverter components over to applicable Tremolux phase inverter components.

Of the parts that don't correlate, the result of drift will be less balancing of gain between halves of the phase inverter, and likely more "pumping" or background trem noise as a result. Leo got a patent on that particular tremolo circuit, because applying it to the common-mode input of the paraphase (the shared cathode resistor) creates a trem signal in-phase in the push-pull output stage. The pulsating volume change when you play gets passed on to the speaker, while the pumping noise when you're not playing gets cancelled by the output transformer. The exception is you still hear some noise due to carbon comp hiss.
Title: Re: 5E9 Tremolux Tremolo question
Post by: Tyrannocaster on May 20, 2012, 11:39:40 am
IIRC, the "drift" (or maybe it was that way originally) that I was able to measure is mostly in resistors and is usually in the range of 15% or so. I have always assumed that the total of all the non-spec values was just a good combination in this particular amp. I don't have a capacitance meter so I can't measure that and I'm sure that's just as important, but over time I have replaced many of the caps with the correct labeled values from the schematic and the amp still sounds great.

My 5D3 has three inputs too. :)

I understand your reasoning behind copying the Tremolux. However, I haven't liked the 5D3 amps I've heard nearly as well and I don't know how much of that is due to the different PI or the octal tubes, or just pure chance. I'm going to try to adapt the trem circuit to the 5D3 because that way even if the tremolo never works right I should still have a very good sounding amp (to my tastes, anyway). I'm sure I'll be back with questions as soon as the trem doesn't work, LOL.
Title: Re: 5E9 Tremolux Tremolo question
Post by: HotBluePlates on May 20, 2012, 07:48:05 pm
I don't know what to tell you, because in general a Deluxe sounds like a Deluxe. My 5E3 copy is probably a bit brighter than the '55 Tremolux I had, but the speaker is also 40-50 years newer.

Note that most resistors in the Deluxe are probably 20% tolerance (no color band). You might have 10% resistors in your amp. Old carbon comps (maybe they still do it this way today) were made in batches, the resistance tested, then the color bands applied to indicate the resulting resistance. There was nothing special about 5% or 10% resistors, except they measured closer to the nominal value than 20% parts. Therefore, a 100k (nominal marked value) resistor measuring between 95-105k was marked as a 100k with a gold (5%) tolerance band. Those that measured 90k - 94.9k and 105.1k -110k were marked 100k and given a 10% tolerance band. All others were left with no tolerance band (indicating 20% tolerance).

As a result, if you have 10% tolerance resistors, you simply won't find any 100k resistors closer to 100k than 95.1k or 105.1k. That's not drift, but a "hollowing out" of the value range due to marking resistor tolerances.

However, you might like the sound of octal tubes. They do sound very slightly different than 9-pin miniatures. You could build the Tremolux with all octal tubes instead of sweating the differences between the Tremolux and Deluxe variants. And of course, you can slightly alter values and tweak things in the amp later. A drastic step (with pluses and minuses) would be to buy an original mid-50's P12Q Jensen for your new amp, which would take out the old vs new speaker factor. I'm quite pleased with my WeberVST speaker (when Ted was still alive he was great about recommending a specific model and set of options to nail the sound of a particular old amp).
Title: Re: 5E9 Tremolux Tremolo question
Post by: Tyrannocaster on May 21, 2012, 05:12:02 am
The speaker issue is a valid one. Mine has a P12Q in it right now but the best sounding speaker I have had in my 5D3 (to my ears, anyway) is an Eminence Legend GB. I love that speaker in the Deluxe. I swapped it out to hear it in something else and haven't put it back yet, but I know it will end up there eventually. It just BARELY fits and allows JJ 6V6s to clear the magnet. The P12Q isn't bad, but the Legend sounds better to me.
Title: Re: 5E9 Tremolux Tremolo question
Post by: roseblood11 on January 08, 2018, 04:35:07 pm
I have a similar question:

Could I use the 5e9a tremolo section to modulate the cathode of a ef86 pentode in a Vox normal channel?
(I'm planning a 3 channel amp with ef86+trem channel and two top boost channels into AC30 power amp in a vintage Vox chassis...)

Regards, Immo
Title: Re: 5E9 Tremolux Tremolo question
Post by: lego4040 on January 09, 2018, 01:55:01 pm
I built the 5E9A Tremolo from scratch with the extreme help of all the folks here that have already commented. I had to drawout layout to scale the execute it onto a blank turret board from Doug  made my own turret press swagging tool( Think thats the name) I wound up using Mercury Mags for the PT as they are or were the only one that makes for that model, I used classictone OT. I can dig through my pics, and part list to give you those part #’s. I used a WGS 12” and I am blown away by this amp. I dont gig and stuff so this amp isnt even broken in yet and it sounds beautiful. Brent Jesse helped me out on choosing NOS tubes, ive never had any issues with his tubes and always picks up the phone
This is the MercuryMag PT I used
(http://www.mercurymagnetics.com/images/logos/mercury/mini/ToneClonePlus2.jpg)
PTFTTP-M '57-'59 Tweed -- lower B+ -- #8160  $165.00
This is the chassis from Mojo I used TWEED NARROW PANEL SUPER STYLE 5F4 / PRO 5E5A CHASSIS
This is the OT http://www.classictone.net/40-18090.html (http://www.classictone.net/40-18090.html)