Ceriatone HRM - Eric Gales Two Rock Please Help

[Fender0740]

Hey everyone, my name is Tim I'm a new member - I won't just hope to get the answer and disappear I would like to contribute to this forum.
I was recommended here by a fellow member on TGP
Think you guys could be the ones to help me here so any input I would greatly appreciate! This was my original question Copied from TGP.

So after weeks of listening, researching and more importantly reading I've realized instead of Marshall type amps that this is probably the best way to go.
I want to achieve or at least get in the ball park of the Eric Gales Two Rock, the thick pronounced mid range, gorgeous low end, articulate note bloom, high gain - some say almost like a germanium fuzz..
I read that the Two Rock EG is a HRM circuit with a lot of other things going on..

So how does one get close to that from a standard Ceriatone HRM?
By no means do I class my self as an expert or even know what I'm really talking about when it comes to Dumbles, but for the people that do I would appreciate anything you have to say that could help me!

The Skyliner circuit sounds like it has a lot to do with the sound of the EG especially the frequencies the bass and mid range is centered over?
The Bluesmaster circuit also sounds like it has something to do with the OD

One thing I know I've got to do is convert it from 6L6's to El34's.
Is there a way of increasing the gain within the HRM circuit, a mod or 10 that will get me there to give me that almost fuzz like tone??
The cleans the Ceriatone HRM gives sounds good to me from online videos and sounds clips, I don't know if there is a way of pronouncing the mid range just a tad more to make it sound more and give it that note bloom to make it more Two Rock esque?

For those that say buy a Two Rock it simply isn't an option as I do not have that type of money the only way I'm doing this is I've inherited some money and know the good man would of wanted me to spend it on something I would love and enjoy and I can think of nothing else!...plus I like a challenge.

Thanks for taking your time to read this guys
Tim

[ToneMerc]

Hey everyone, my name is Tim I'm a new member - I won't just hope to get the answer and disappear I would like to contribute to this forum.


For those that say buy a Two Rock it simply isn't an option as I do not have that type of money the only way I'm doing this is I've inherited some money and know the good man would of wanted me to spend it on something I would love and enjoy and I can think of nothing else!...plus I like a challenge.


Tim

Buy a TR EG so it can documented here and then you sell it. Then in the coming months maybe Ceriatone will ofter an HRM Memphis model.

TM

[halfbackstrat]

Ok, let's figure out what we know to start off with.

I love TR amps and I'd love to help figure out what's going on inside the amps they no longer produced.

Andertons used to carry the EG sig, here's a gutshot they posted. It's low res but it's a start!

[img:500:500]http://www.andertons.co.uk/Products/i/x ... cgales.jpg[/img]


NB: This picture is of the 100W SS rec version.

Now, the controls on the EG sig are,

Front: Input, Channel 1 (Gain, Treble, Middle, Bass, Master) Channel 2 (Gain, Treble, Middle, Bass, Master) Standby, Pilot Light.
Back: AC On, Fuse, 4, 8, 16 Ohm outputs, Footswitch, Effects Loop Send & Return.

The amp came in two configurations, a 100W SS rectified and a 50W Tube rectified version. I think it would be really interesting to design the tube rectifier section for these amps!
The gain channel tone controls are confirmed as being a post OD tonestack, i.e HRM as you suggested.
The Andertons website lists it as having a Precision power supply, which I'm sure a few of the guys here could fill you in on better than i could, I don't want to say something wrong about it! But effectively instead of each B+ filter having a resistor and capacitor in series to ground, it has I think two caps and two resistors. With each cap and resistor in parallel pairs and then each pair in series with eachother. If that makes sense?

[Fender0740]

[img:500:500]http://www.andertons.co.uk/Products/i/x ... cgales.jpg[/img]

I think it would be really interesting to design the tube rectifier section for these amps!

Wow a great reply thanks!
The 50w was exactly the one I was looking to get in the ball park with, in every clip I've heard of that amp (to me) it sounds nothing short of amazing! Yes that did make sense thanks Matt thanks for the gut shot too

[halfbackstrat]

You're most welcome, anything I can do to help.

I've not seen a lot of discussion on this forum about Tube rectifiers because I know a lot of guys don't like them for various reasons, usually reliability.
Also, I've not heard of HAD himself building any amps with tube rectifiers, however there are so many undocumented Dumble's who knows!

Anyway, assuming TR have a fairly standard set up for their tube rectifier, the one in the Matt Schofield sig might be the same.

Attached is a gutshot of it.

There's also a version of the Custom Reverb Sig 3 available with TR,

Attached is a gutshot of it also.


So when considering a design for this amp, your PT will have to have a tap for the rectifier heaters, the 6.3V tap for power tubes and preamp tubes will not work, 5AR4/GZ34 rectifier tubes as these employ, draw 1.9A at 5V so you'll need a 5V 4A tap.

[Fender0740]

You're most welcome, anything I can do to help.

I've not seen a lot of discussion on this forum about Tube rectifiers because I know a lot of guys don't like them for various reasons, usually reliability.
Also, I've not heard of HAD himself building any amps with tube rectifiers, however there are so many undocumented Dumble's who knows!

Anyway, assuming TR have a fairly standard set up for their tube rectifier, the one in the Matt Schofield sig might be the same.

Attached is a gutshot of it.

There's also a version of the Custom Reverb Sig 3 available with TR,

Attached is a gutshot of it also.


So when considering a design for this amp, your PT will have to have a tap for the rectifier heaters, the 6.3V tap for power tubes and preamp tubes will not work, 5AR4/GZ34 rectifier tubes as these employ, draw 1.9A at 5V so you'll need a 5V 4A tap.

Maybe a stupid question but Is there a way of making them more reliable?

Again thanks for the info it really does help and im jotting down every last piece of info!
Dont know if this is aloud on this forum so if its not let me know and ill delete the post but I just found this thread https://tubeamparchive.com/viewtopic.ph ... eric+gales
great gut shots courtesy of "mrfender" Thank you!

[halfbackstrat]

Oh yeah, I totally forgot that thread had been posted!
I even commented at the bottom

A good read about rectifiers will be found here (really a good read about all facets of amp construction!): http://www.valvewizard.co.uk/fullwave.html
Especially the parallel section, you'll want to GZ34 tubes in parallel to rectify a 50W amp without a massive amount of "sag".

As for making them more reliable, I'm not sure really. It's not that they're unreliable per se, it's just that tubes are never as reliable as solid state.
I suppose you could run the heater voltages for the two tubes in series, that means that if one valve breaks the other won't get instantly overloaded and also break. However you'd need a 10V tap then instead of a 5V tap for parallel.

[Fender0740]

A good read about rectifiers will be found here (really a good read about all facets of amp construction!): http://www.valvewizard.co.uk/fullwave.html
Especially the parallel section, you'll want to GZ34 tubes in parallel to rectify a 50W amp without a massive amount of "sag".

As for making them more reliable, I'm not sure really. It's not that they're unreliable per se, it's just that tubes are never as reliable as solid state.
I suppose you could run the heater voltages for the two tubes in series, that means that if one valve breaks the other won't get instantly overloaded and also break. However you'd need a 10V tap then instead of a 5V tap for parallel.

That was a good read thanks for that
It says the EG model runs on El34's would GZ34;s make that much of a difference? I'm learning a lot here should of joined a long time ago, very much appreciated Matt!

[halfbackstrat]

EL34s are power tubes and GZ34s are rectifier tubes.
The full tube compliment in a TR EG is 3 12AX7 preamp tubes, 2 x EL34 power tubes and 2 GZ34 rectifier tubes.

[Fender0740]

EL34s are power tubes and GZ34s are rectifier tubes.
The full tube compliment in a TR EG is 3 12AX7 preamp tubes, 2 x EL34 power tubes and 2 GZ34 rectifier tubes.

please ignore that im so bloody stupid, el34's because its solid state rectified, GZ34's because its TUBE rectified..wasn't thinking sorry

[Fender0740]

So am i right thinking the EG is based on the Skyliner HRM circuit, or would you say its the Bluesmaster circuit?

[halfbackstrat]

EL34s are power tubes and GZ34s are rectifier tubes.
The full tube compliment in a TR EG is 3 12AX7 preamp tubes, 2 x EL34 power tubes and 2 GZ34 rectifier tubes.

please ignore that im so bloody stupid, el34's because its solid state rectified, GZ34's because its TUBE rectified..wasn't thinking sorry

The GZ34's don't replace the EL34s directly.
You could make a 50W solid state rectifier with three 12AX7s and 2 EL34s and then the other two tube holes plugged up. The EL34s are there only to amplify the sound they don't rectify the signal.

The power supply section has to be "rectified" from AC to DC, this can be done with diodes as they only allow current to pass in one direction, i.e Solid state rectified, or passing the signal through a rectifier tube such as a GZ34 "tube rectified".
The reason there is no 100W tube rectified version is the amp would need 3 12AX7s in the preamp, four EL34s (to get the 100W) and 2 GZ34s to rectify the power supply. There's simply not enough room!

[Fender0740]

I'm with you Matt, had a really blank moment there!

well I'm definitely wanting to try to make it the 50w Tube rectified version as I have no reason to want 100w

In regards to the circuit what would you say the EG is based on, Skyliner HRM or Bluesmaster HRM? or something entirely different?

[Colossal]

Fender0740,

For some amps, I really like the sound a tube rectifier gives, especially the GZ34/5AR4. In conjunction with the right combination of filtering, you can get a remarkable amount of girth and fatness and depth that you can control with technique. I would suggest, if you can afford them, to try to acquire some real Mullard 5AR4s. They have a depth to them that is fantastic. They command a high price these days (I think Brian May bought them all up LOL) but they will last a lifetime so are a good investment. Barring that, the Sovtek 5AR4 is a great sounding current production tube, and 1/10 the price. I haven't had one fail yet.

Some guys use a resistor in series with B+ to "simulate" the sag/compression contributed by a rectifier tube, but the true response of a rectifier tube is non-linear so this simulation is an approximation(but "good enough" for some). For others the sound of a rectifier tube is essential to feel, compression, but others demand extreme reliability so their personal bias may be towards solid state rectification. Rectifier tubes of the same designation but different manufacture do sound different so this is another reason some don't want to hassle them: reproducibility of tone. If you go the tube recitifer route with your build, be prepared to roll some tubes to truly dial in the tone that suits your tastes.

Just a few cents...

[Fender0740]

Fender0740,

For some amps, I really like the sound a tube rectifier gives, especially the GZ34/5AR4. In conjunction with the right combination of filtering, you can get a remarkable amount of girth and fatness and depth that you can control with technique. I would suggest, if you can afford them, to try to acquire some real Mullard 5AR4s. They have a depth to them that is fantastic. They command a high price these days (I think Brian May bought them all up LOL) but they will last a lifetime so are a good investment. Barring that, the Sovtek 5AR4 is a great sounding current production tube, and 1/10 the price. I haven't had one fail yet.

Some guys use a resistor in series with B+ to "simulate" the sag/compression contributed by a rectifier tube, but the true response of a rectifier tube is non-linear so this simulation is an approximation(but "good enough" for some). For others the sound of a rectifier tube is essential to feel, compression, but others demand extreme reliability so their personal bias may be towards solid state rectification. Rectifier tubes of the same designation but different manufacture do sound different so this is another reason some don't want to hassle them: reproducibility of tone. If you go the tube recitifer route with your build, be prepared to roll some tubes to truly dial in the tone that suits your tastes.
Just a few cents...

Colossal - Thank you for that, I have read that the tubes you use in this amp with the tube rectifier does make a HUGE difference to the overall sound of the amp. The Mullard 5AR4's is what I was looking at as they are what people have recommended but the price tag is steep! Then again if that's what gives the best tone I may just have to dove a little deeper into my wallet and if they dont work for my tastes then I'm sure I can sell them and find something that does