5AR4 Rectifier tube

My only amp that uses a tube rectifier instead of a solid state rectifier is my Allen Sweet Spot. It has the 5AR4, which is also known as the GZ34.
 
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A good explanation from the Soldano website:
An amp with a tube rectifier tends to sound much spongier in the bottom end. Low frequency notes take more current through the power tubes to reproduce. This increased current causes a voltage drop in the rectifier tube and the amp loses power. So, when more power is actually needed, the amp gives less. Because of this, a tube rectifier amp will sound spongy and more distorted at high volumes. This, probably more than anything, is what gives a vintage amp its sound and color.

The rest of the story...:
Tube vs. Solid State Rectifiers « Soldano Custom Amplification
 
syscokid said:
A good explanation from the Soldano website:
An amp with a tube rectifier tends to sound much spongier in the bottom end. Low frequency notes take more current through the power tubes to reproduce. This increased current causes a voltage drop in the rectifier tube and the amp loses power. So, when more power is actually needed, the amp gives less. Because of this, a tube rectifier amp will sound spongy and more distorted at high volumes. This, probably more than anything, is what gives a vintage amp its sound and color.

The rest of the story...:
Tube vs. Solid State Rectifiers « Soldano Custom Amplification
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I put in a bid for a lot of used tubes. Unfortunately, the seller is not responding to my offer, but if I get it, the 5AR4s are your for the cost of shipping if you want them.
 
I’ve had amps with them in the past. Won’t use tube rectifiers again, they’re not tight enough at volume. Even when I had an amp that had switchable rectifiers I always used the SS one.
 
gball said:
What kind of player wants a flubby low end and power sag? I can’t see how that would benefit anyone, high gain or clean.
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Ha ha... "flubby low end" doesn't sound very appealing. But my Sweet Spot with that 5AR4 rectifier tube does not have a "flubby" low end. But a little sag does soften the initial attack applied to the strings. It also creates a bit of note blooming. IMO, a titbit of sag helps overdrive pedals sound amazing thru this amp.

Now in regards to some Mesa's who have the feature to switch from tube rectification to diode rectification, like the Mark V's, their specs call for a 5U4. The 5U4's are going to produce more sag than the 5AR4s. Mesa is probably using the 5U4s so there will be a more noticeable distinction between selecting SS or tube rectification.

From the KCA website:
Rectifier Interchangeability and it's relation to Clean Headroom

Here's the list of the most common guitar amp rectifiers in order of most to least clean headroom (highest to lowest voltage output) and least to most sag:

1) Solid State Rectifier (NOT Weber Copper caps)
2) 5AR4/GZ34
3) GZ37 (3 amp filament current)
4) 5V4G/A (Possibly lower if plate current of the power tubes is high enough)
5) 5U4/G/A/B (3 amp filament current)
6) 5R4G/A/B
7) 5Y3G/B

And for the whole article:
Rectifier comparison and interchangeability chart | KCA NOS Tubes & Amplifier Repair
 
I only have five guitar amps where I use a GZ34 I don't notice sag at all or flabby low end.
One amp I own has a 5U4 and put a JBL 12" speaker in it.
 
gball said:
What kind of player wants a flubby low end and power sag? I can’t see how that would benefit anyone, high gain or clean.
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I can see how a certain degree of sag could lend a degree of space and breath to more clean styles, if it’s no more than a subtle nuance.

Of course, if it’s too extreme, it would be distracting. I can also see how it could be detrimental to really high gain sounds.

To be totally honest, my best-sounding amp is my ‘73 Fender Champ. It has a 5Y3 rectifier. It has a musical character all its own. No flubby low end. Just very pleasing.

The speaker is not the original, though. It is an alnico Weber with a larger voice coil than the stock speaker.
 
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RVA said:
It appears that t by ey also have solid state plugin replacements for the 5ar4
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Yes they do. Here's mine:
IMG_1464.JPG

I've never used it, but I bought it for my Sweet Spot. Currently this amp is tube rectified and powered with two 6V6s with a spec output of 18 watts. I have the option to operate this amp at 25 watts by installing a plug-in SS rectifier, installing a pair of 6L6s, and a simple bias adjustment.
 
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smitty_p said:
Ignore all of us.

Listen for yourself and decide what YOU like!
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Have you not been watching -- we must STEER the question-ie to buy thing s he doesnt need-- or want -- in a selfish orgy of learning what we ourselves do or dont want ---

-- me -- I want a cheeseburger actually ------
 
eSGEe said:
Have you not been watching -- we must STEER the question-ie to buy thing s he doesnt need-- or want -- in a selfish orgy of learning what we ourselves do or dont want ---

-- me -- I want a cheeseburger actually ------
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I already did...I bought MORE TUBES!!!!!!!!!!!!!!!
 
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