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Hi all.

A few years back, I picked up an old Elk amp (head and 2x10 cab) The head is a 2 x 7189 power section, EZ81 rectified, with reverb and tremolo. Single channel with bass and treble controls. The 2 x 10 cab has old (Echo) Alnico speakers in it, and it sounds great. The head actually works, but is a bit temperamental, buzzing and humming intermittently, and also sounds a bit thin.

I am at a crossroads, where either I re-build the amp to original specs (I do have the schematic) by replacing all the old caps etc (maybe the OT too) and get it working 100%, or I need to rebuild the head, using another circuit in there altogether.

I am reluctant to scrap the original circuit entirely, since it is rather unique sounding, and I probably won't find another in a hurry, but on the other hand, it might be useful to replace it with a circuit that is more useable and "classic". I was thinking along the lines of a BF Princeton, with no reverb.

I don't really know what the current circuit could potentially sound like, were it to be re-capped etc, to it's original state. I may go to a lot of trouble, only to find that even a perfect specimen of such a design doesn't sound that great anyway. I do also have concerns too that 7189 power tubes may be difficult (and expensive) to source.

Does anyone here have experience, either good or bad with these amp circuits, and is it worth restoring, or is it better to replace the circuit with something different (better) ?

I already have a Bassman 10 (4 x 10) combo, an 18 watt clone (head) and a 50 watt JMP (head), so I do have some "dirty" amps, and would like to have a small (read transportable) clean amp - hence my wanting to convert to a 6V6 BF Princeton. I do a lot of studio recording, and I've heard great things about the Princeton circuit when used in the studio.

Any advice?

Thanks in advance.

I guarantee that you´ll have to change all the coupling caps,as they tend to leak. Scratchy pots and a thin sound is a sign of that.
Recapped these babies actually sounds quite fat with a proper speaker.

Regards.

I guarantee that you´ll have to change all the coupling caps,as they tend to leak. Scratchy pots and a thin sound is a sign of that.
Recapped these babies actually sounds quite fat with a proper speaker.

Regards.

Hi thanks for that reply. Much appreciated.

I realize that if I keep the original circuit, it'll need to be re-capped and re-tubed. I would probably replace the old resistors too, and while I was at it possibly the wiring too. This thing is a pretty sloppy build, and the components used look cheap and nasty. A complete re-build would probably be necessary to just make the wiring look neat to begin with. Even the OT looks a bit small.

My real question is, does anybody out there feel that this amp (circuit) sounds good enough to warrant re-building (taking into consideration my concerns initially stated above) I don' really want to go through all the effort to have it sound "okay"

Anyone else re-built one of these?

Hello Bendo,
I've never sniffed the Amp in question.
But FWIW;
7189's have a higher plate rating over EL84 So check your plate voltage,, if it's near 400 VDC then there are cheap Russians,
6P14P (or something like that) that can also handle the higher plate Volts..Don't use EL84 if the plates are around 400VDC.

You mentioned tone,,, it's over rated IMO lol.

7189 is going to sound like a EL84 amp with an extra 1.5 watts of power,, so it's just a slightly bigger bottle that can handle a higher plate voltage.
As you already have plenty of ODriven EL84 type Amps then you might enjoy building a 6V6.

6V6 are a VERY different dog to play with and will respond in a very different manner. My guess is the Amp PSU will likely be 400 ish VDC and JJ6V6 will work safely at that voltage.
Don't quote me but my memory thinks
EL84 12 watts- 300 VDC plates - TC 11,200
7189 13.5 watts- 400VDC plates - TC 11,300

6V6, 14 watts- 400VDC plates - TC 3,800

Having built both EL84 powered amps and 6V6 Amps here's my observations;

El84 types;
Easy to distort ,,can be tricky to get good clean due to the nature of true pentodes,,
(they distort because they have big TC)

6V6;
fixed bias, they run very clean but if you want the converted OD that gets raved about then,
stick to Cathode biased circuits. just look up all the early deluxe circuits for ideas.

Phil.

if you want my opinion, I would restore it. why not have something cool and different? anyone can have a Princeton. not everyone can have an Elk Custom 30!

Hi guys.

Thanks for the responses. Much appreciated.

I'm still undecided as to what I'm going to do. After some more reading up, it seems also that because of the construction method used on these amps, there have been reports of the whole turret board becoming conductive (fender rot). This amp is getting very little love by the majority of users. I saw a post somewhere from (Bruce) Mission Amps stating that he had done some repair work on a few in years gone by, and found them to be anything but well built or designed, as well as using VERY sketchy parts.

I might just buy a Princeton kit, replace the guts and be done with it. Not too sure I want to be in for the fight.

by RnFR » 04 Oct 2011, 17:00

if you want my opinion, I would restore it. why not have something cool and different? anyone can have a Princeton. not everyone can have an Elk Custom 30!

RnFR, I'm attached to those sentiments, but not necessarily the practicality.

I often feel the idea of owning something is often better than actually owning it.

It's your amp, you really have to decide if you want to restore the original circuit. You can always restore it and then start tweaking what you don't like about it. I agree almost all the components will have to be replaced.

Myself, I've never heard a "great"-sounding Elk, I've never even heard one i would call "good", and I've never run into a player or tech that liked them much either. They pop up from time to time, often generating interest amongst the uninitiated, because they completely stole the Fender BF/SF cosmetics and they look like Japanese clones of Fenders. BUT they aren't Japanese clones and use their own circuits and IMHO, crappy parts.

To me, much like many of the old Univox stacks, when I see one, i see a chassis/cabinet I can use aI scrap the rest without even plugging it in.

wyatt wrote:It's your amp, you really have to decide if you want to restore the original circuit. You can always restore it and then start tweaking what you don't like about it. I agree almost all the components will have to be replaced.

Myself, I've never heard a "great"-sounding Elk, I've never even heard one i would call "good", and I've never run into a player or tech that liked them much either. They pop up from time to time, often generating interest amongst the uninitiated, because they completely stole the Fender BF/SF cosmetics and they look like Japanese clones of Fenders. BUT they aren't Japanese clones and use their own circuits and IMHO, crappy parts.

To me, much like many of the old Univox stacks, when I see one, i see a chassis/cabinet I can use aI scrap the rest without even plugging it in.

Hi wyatt

You've confirmed my suspicions..... that this amp is nothing special. In-fact, it's probably quite the opposite.

It does look pretty cool, and I like the fact that it's easily transportable, and that it's a head / cab configuration. Find that quite useful for recording, since the head and cab can be put in different rooms. I actually like the way the 2x10 cab sounds too. I've used it with a couple different heads, and it sounds pretty sweet.

The amp circuit though, I'm not all that impressed with. The reverb is very overbearing and the Tremolo is very "throbby" - not too subtle or smooth. The amp gets dirty pretty quick, at pretty low volume too, but it's a loose, mushy distortion that I don't find that useful. It' also unbelievably bright.

The reason I'm interested to know wether this amp could potentially sound great, is that I've only ever heard my own ELK, and have no reference point as to wether the amp sounds pretty weak because so many components are old and cheap, or because it's just a bad design. It seems as I learn more about it that the best thing to do is to gut it, and build something that I actually like instead.

Thanks for the advice.

Bendo031 wrote:

wyatt wrote:It's your amp, you really have to decide if you want to restore the original circuit. You can always restore it and then start tweaking what you don't like about it. I agree almost all the components will have to be replaced.

Myself, I've never heard a "great"-sounding Elk, I've never even heard one i would call "good", and I've never run into a player or tech that liked them much either. They pop up from time to time, often generating interest amongst the uninitiated, because they completely stole the Fender BF/SF cosmetics and they look like Japanese clones of Fenders. BUT they aren't Japanese clones and use their own circuits and IMHO, crappy parts.

To me, much like many of the old Univox stacks, when I see one, i see a chassis/cabinet I can use aI scrap the rest without even plugging it in.

Hi wyatt

You've confirmed my suspicions..... that this amp is nothing special. In-fact, it's probably quite the opposite.

It does look pretty cool, and I like the fact that it's easily transportable, and that it's a head / cab configuration. Find that quite useful for recording, since the head and cab can be put in different rooms. I actually like the way the 2x10 cab sounds too. I've used it with a couple different heads, and it sounds pretty sweet.

The amp circuit though, I'm not all that impressed with. The reverb is very overbearing and the Tremolo is very "throbby" - not too subtle or smooth. The amp gets dirty pretty quick, at pretty low volume too, but it's a loose, mushy distortion that I don't find that useful. It' also unbelievably bright.

The reason I'm interested to know wether this amp could potentially sound great, is that I've only ever heard my own ELK, and have no reference point as to wether the amp sounds pretty weak because so many components are old and cheap, or because it's just a bad design. It seems as I learn more about it that the best thing to do is to gut it, and build something that I actually like instead.

Thanks for the advice.

It's probably sounding weak due to worn out caps/resistors/tubes/suspect solder joints,etc so I'm guessing that if the amp is re-built using all new parts, it may sound a bit better, how old is the amp?, the caps used in vintage tube amps were reckoned to have a useful life of about ten years before they started failing, this is because the electronics parts industry was still pretty new and manufacturing techniques were still to be refined....

DrNomis wrote: It's probably sounding weak due to worn out caps/resistors/tubes/suspect solder joints,etc so I'm guessing that if the amp is re-built using all new parts, it may sound a bit better, how old is the amp?, the caps used in vintage tube amps were reckoned to have a useful life of about ten years before they started failing, this is because the electronics parts industry was still pretty new and manufacturing techniques were still to be refined....

Hey DrNomis.

Thanks for that, I realize that this would be the case. The amp will definitely sound "better" once I've re-capped it and sorted out bad components etc, but wether or not it will sound "great" is my concern. I don't really want to go through all the hassle of re-building the amp, only to find that it sounds okay. If that were the case, I'd rather build a classic sounding circuit in there.

The amp is probably from the late 60's, so there are definitely old, dead caps in there.

Bendo031 wrote:

DrNomis wrote: It's probably sounding weak due to worn out caps/resistors/tubes/suspect solder joints,etc so I'm guessing that if the amp is re-built using all new parts, it may sound a bit better, how old is the amp?, the caps used in vintage tube amps were reckoned to have a useful life of about ten years before they started failing, this is because the electronics parts industry was still pretty new and manufacturing techniques were still to be refined....

Hey DrNomis.

Thanks for that, I realize that this would be the case. The amp will definitely sound "better" once I've re-capped it and sorted out bad components etc, but wether or not it will sound "great" is my concern. I don't really want to go through all the hassle of re-building the amp, only to find that it sounds okay. If that were the case, I'd rather build a classic sounding circuit in there.

The amp is probably from the late 60's, so there are definitely old, dead caps in there.

That basically means that the caps in the amp are probably at least 40 years old or something like that, if the power and output transformers are okay then I can't see why you couldn't gut the amp and re-build it as something better, I remember seeing a couple of interesting amp mods in two of my Guitar Player magazines, they were by a guy called John McIntyre, or something like that, one mod was for a Fender Bassman Head to turn it into the ultimate Blues amp, the other was for modding a Fender Princeton into something he called the Prince O Wails, try googling for those articles, I wouldn't mind doing something like that myself, always been wanting to get into building my own amps and stuff, especially on Turret Boards....

I did some work on my little Legacy Valve Edition 5 Plus 5 Watt Single-End Class-A combo amp, firstly to fix an issue with some fue holders, and secondly to get rid of some background hum, the amp works pretty good now...

If you ever need help with your Elk amp, just let me know....

The nice thing about old curios like this is you could never buy a new chassis, transformers, sockets, and knobs for anywhere near the price you can get some basketcase amp. And I think the Elk cosmetics have a cool old-school look to boot. '

Heck, for that matter, most odd-ball Fenders (super Twin Reverb, Quad Reveerb, Ultralinear models, etc.), despite their increasing prices, are twice as much in parts as they are whole.

Hey all.

I've decided to go ahead and gut the old ELK, and build a DR Z Z28 circuit in there.

Any thoughts? I've been advised to use new parts for almost everything (tube sockets, transformers etc.) Does anybody have any experience they'd be wiling to share?

Thanks.

Bendo031 wrote:Hey all.

I've decided to go ahead and gut the old ELK, and build a DR Z Z28 circuit in there.

Any thoughts? I've been advised to use new parts for almost everything (tube sockets, transformers etc.) Does anybody have any experience they'd be wiling to share?

Thanks.

Hard to see without seeing it in person.

Chances are the tube sockets are much higher quality than most modern replacements. I buy NOS or used octal sockets for my builds because I'm not not happy with any of the modern ones.

Transformers? May or may not be ideal for any specific type of circuit. You have to find out the secondary voltages and currents and go from there.

I probably wouldn't try and reuse the pots, AC cord, etc.

So I've gone ahead and stripped the chassis:
Planning on building a 5e3 circuit instead of a DR. Z Z-28. I've had problems with EF86 channels before, and due to reliability issues opted to go with a triode preamp instead.

So here's the thing. I'm planning on using the PT from the ELK, since it's rated 320v - 0 - 320v on the secondaries. It has a 6.3v tap for the rec tube, (EZ81 in this case) and another 6.3v tap for the filaments of the other tubes. No 5V tap. I would have otherwise used the traditional 5y3 rectifier. Is there a reason why I shouldn't use the EZ81 in place of the 5Y3?

The OT has the right primary for a 6V6 class A/B power section, but only has a secondary tap for 4 ohms. I'm planning on using the build as a head with a variety of cabs, and would like the ability to mix and match, so therefore I'm going to have to use a modern replacement with 4 / 8 / 16 ohm secondaries.

I did measure the PT, and although rated at 320v, I did measure 350 when the PT was under no load. Will this be okay once I have the tubes in?

Any advice would be greatly appreciated.