Speaker upgrade for Hot Rod Deluxe

[kipper]

I'm thinking of upgrading the speaker in my Hot Rod Deluxe. I like Celestion speakers and these can be had for very good prices this side of the pond, although their prices are going up on 1st October...hence why I want to get one ordered soon.

I've read both good and bad things about the two speakers I have in mind:


A) Celestion Vintage 30

These were fitted as standard on the "Texas Red" Limited Edition run of HRDx amps

or

B) Celestion G12 Century Vintage

These were fitted as standard on the "White Lightning" Limited Edition run of HRDx amps


The Century Vintage costs a little more and seems to have the slightly better reviews overall, with some complaining that the Vintage 30 is a little too midrange-heavy.

Anyone have any opinions on these? Anyone heard these in a HDRx amp (including the LE models I mention above)?

Thanks in advance.

 

[mrmudcat]

I have a limited edition hrd that has the vin 30.I would take this speaker for sure:beer:

 

[kipper]

I have a limited edition hrd that has the vin 30.I would take this speaker for sure:beer:

Thanks for your input mrmudcat!

Can I ask...

Which HRDx limited edition do you own?

Do you find this speaker to be really loud? (the HRDx is loud enough with the stock Eminence speaker, and then some!).

I have read the Century Vintage is considerably quieter than both the stock Eminence speaker and the Celestion Vintage 30...which is no bad thing for me, given that I only play at home, and this amp is a beast to tame in terms of volume!

I use a Z Air Brake to attenuate and I'm not sure if replacing the stock speaker with an even louder speaker with help things much

What about the midrange? Do you find this to be very prominent? I ask because the negative reviews of this speaker/amp combination are fairly consistent in this regard.

 

[Spudman]

I still have the stock speaker in mine and have always thought that a different speaker could really help the amp out. I have a Warehouse V30 that I could stick in it. I just haven't done it yet.

 

[Tone2TheBone]

I have a set of Celestion Vintage 30s in my Marshall. Love them in that amp but yeah they do tend to be upper mid-y but with the tone knobs on the amph I can dial in the tones I want. I also have one of the Warehouse Guitar Speakers version of the same speaker, the one Spud mentioned...the Veteran 30 and holy cow is it a dang good speaker. Nice balanced sound and I have that one in my Blues Jr. amph. I don't know if you're willing to order from WGS but I would recommend the Veteran 30 speakers but if you can get the Vintage 30s for a good price yeah do that too.

 

[kipper]

Thanks for the comments everyone.

As it happens I was actually talking to an amp tech the other day, who claimed that the Vintage 30 will make the HRDx seem even louder than the stock Eminence speaker as it's more efficient.

That is NOT the result I was looking for with the HRDx! It's already one hell of a loud amp. I personally think the HRDx amp is a great value amp, and looks really cool but it's really freakin' loud!!!

Even when I am attenuating using the excellent Dr Z Air Brake (which is pretty much all of the time) it's a very loud amp and I rarely turn up past 2 at home.

I've also read on Justin Holton's excellent HRDx website that the majority of people who change the speaker apparently end up putting the stock Eminence Legend 125 back in!

Maybe I'll hold fire on the tinkering for now...

 

[ShortBuSX]

You seem really deadset on getting a speaker, but it sounds like your intent is acutally tamming this amp for bedroom use? And if the speaker is going to make it louder then you dont want the speaker...even if its going to sound better.

So Im gonna try and sway you another dirrection entirely...get new tubes instead.

If youve got OEM powertubes, some new Winged C powertubes will get rid of that brittle/crackly tone and will add more sparkle and shimmer.
And if you get new preamp tubes, Id suggest getting two 12AT7's(for V1 and V3) and one 12AX7(for V2)(I like JJ's for the preamp)...these will tame your amp for bedroom level AND will shape your tone in a more desireable dirrection.

 

[tunghaichuan]

Thanks for the comments everyone.
As it happens I was actually talking to an amp tech the other day, who claimed that the Vintage 30 will make the HRDx seem even louder than the stock Eminence speaker as it's more efficient.

I've also read on Justin Holton's excellent HRDx website that the majority of people who change the speaker apparently end up putting the stock Eminence Legend 125 back in!

So the Eminence Legend 125 is the stock speaker in your amp? Do you mean 1258? If so, it has the same sensitivity as the Vintage 30: 100db/watt/meter.

http://www.eminence.com/guitar_speaker_detail.asp?model=LEGEND1258&speaker_size=12&SUB_CAT_ID=4

http://professional.celestion.com/guitar/products/classic/spec.asp?ID=4

The Vintage 30 my seem to sound louder due to the different EQ curve, though.

tung

 

[tunghaichuan]

So Im gonna try and sway you another dirrection entirely...get new tubes instead.

I agree. The Eminence Legend series are fine sounding speakers by all acounts.

If youve got OEM powertubes, some new Winged C powertubes will get rid of that brittle/crackly tone and will add more sparkle and shimmer.

What are the stock power tubes in the HRDlx? The Fender web site says "6L6 Groove Tube output tubes" which could be any current modern production 6L6 types. The Winged C would probably be an improvement.

And if you get new preamp tubes, Id suggest getting two 12AT7's(for V1 and V3) and one 12AX7(for V2)(I like JJ's for the preamp)...these will tame your amp for bedroom level AND will shape your tone in a more desireable dirrection.

Not picking on you ShortBuSX, but I would recommend 5751s or 12AY7/6072s over the 12AT7. Why? The 5751 and 12AY7/6072 are lower gain versions of the 12AX7, the 12AT7 is not. The 12AT7 has different operating specs. One things that concerns me about putting a 12AT7 into a modern-production Fender amp is that they almost surely use 1/4 rated resistors. The 12AT7 is capable of drawing more current than a 12AX7 and the resistor values are all wrong for the 12AT7.

If you've done this and it works for you, then more power to you. But knowing what I know, I personally wouldn't do it without upgrading the appropriate resistors with 1/2W types with values more in line with what a 12AT7 would like to "see." FWIW.

my $.02

tung

 

[M29]

Eminence Texas Heat is less efficient (will be less loud)than most and sounds good. Just a thought. They get pretty good reviews.

M29

 

[TS808]

Eminence Texas Heat is less efficient (will be less loud)than most and sounds good. Just a thought. They get pretty good reviews.

M29

Good suggestion. The Texas Heat has some nice deeper midrange and tames the highs and lows. The Eminence Red White and Blues is also a good choice, but alot of folks either do the Texas Heat or Swamp Thang in the Fender amps.

 

[TS808]

You seem really deadset on getting a speaker, but it sounds like your intent is acutally tamming this amp for bedroom use? And if the speaker is going to make it louder then you dont want the speaker...even if its going to sound better.

So Im gonna try and sway you another dirrection entirely...get new tubes instead.

If youve got OEM powertubes, some new Winged C powertubes will get rid of that brittle/crackly tone and will add more sparkle and shimmer.
And if you get new preamp tubes, Id suggest getting two 12AT7's(for V1 and V3) and one 12AX7(for V2)(I like JJ's for the preamp)...these will tame your amp for bedroom level AND will shape your tone in a more desireable dirrection.

The problem I had with my Hot Rod Deville was also the volume pots. It's really hard to keep those amps at bedroom level use as the volume jump seems to really be between 1 and 4 and then gradually increases at a decreasing rate. I wish Fender would go with a volume pot that is more tame and allows for a more even volume increase on the drive channel.

The tube swap is a good idea for sure, along with having a tech change the volume pots (which voids the warranty though)...then I think it's a very good amp.

 

[kipper]

Some interesting suggestions here y'all.

Even with the Z Air Brake attenuator (which I think is very good btw), this amp is a volume beast! I am, overall, generally happy with the sound I can get at bedroom practise levels with this amp (I do live in a detached house!), my ME-50 (I run the amp completely clean on the clean channel and use the Boss to get OD and distortion), a GE-7 EQ pedal and the Z Air Brake.

But alas...I am a born tinkerer

I had considered swapping the tubes as it happened...a very popular choice seems to be a change in the power amp section with the THD Yellow Jackets (to replace the stock 6L6 Groove Tubes).

These have got some rave reviews from people who have installed them in HRDx amps over on HC, although with this particular mod the amp seems to then become some sort of Fender/Vox AC15 type hybrid in character and gone is the big full "Fender clean" sound which attracted me to the amp in the first place. IMHO a good clean sound can have anything added to it and sound good and IMHO this amp - for the money - gets you closer to that Fender clean tone to build on more so than any other amp (unless you spend twice the money).

Although the plus side with the THD Yellow Jackets is (supposedly) the power is greatly reduced and the amp is more like a 15-watter with those tubes installed. Not sure I believe the "Class A" marketing hype though!

Certainly some of the comments and suggestions here are providing me with more food for thought...

 

[kipper]

The problem I had with my Hot Rod Deville was also the volume pots. It's really hard to keep those amps at bedroom level use as the volume jump seems to really be between 1 and 4 and then gradually increases at a decreasing rate. I wish Fender would go with a volume pot that is more tame and allows for a more even volume increase on the drive channel.

The tube swap is a good idea for sure, along with having a tech change the volume pots (which voids the warranty though)...then I think it's a very good amp.

The OD channel uses a linear pot for sure. When I spoke to an amp tech recently about this...the clean channel (the only I use) already uses an audio taper pot. According to him, placing with a higher value one may help (say a 500K pot) but not a great deal apparently. He said the Air Brake (or other good quality attenuator) was the best way to tame the volume.

At least with the attenuator I am not going to void the warranty, which a volume pot mod would. I've got over 4 years to go on the warranty!! I don't know about speaker or tube changes though, I presume they don't void it but I can't be certain about that (they can easily swapped back to the originals so I would presume not).

 

[kipper]

So the Eminence Legend 125 is the stock speaker in your amp? Do you mean 1258? If so, it has the same sensitivity as the Vintage 30: 100db/watt/meter.

http://www.eminence.com/guitar_speaker_detail.asp?model=LEGEND1258&speaker_size=12&SUB_CAT_ID=4

http://professional.celestion.com/guitar/products/classic/spec.asp?ID=4

The Vintage 30 my seem to sound louder due to the different EQ curve, though.

tung

Yes, I did mean the Eminence 1258. Seems like the Celestion Vintage 30 may not be the best choice, although I wonder if that would be also hold true if I decide to put THD Yellow Jackets in the amp.

Decisions, decisions! :rockon:

 

[tunghaichuan]

Although the plus side with the THD Yellow Jackets is (supposedly) the power is greatly reduced and the amp is more like a 15-watter with those tubes installed. Not sure I believe the "Class A" marketing hype though!

What some amp manufacturers mean when they say "Cass A" is "15-18 watt, Class AB, push-pull, cathode-bias, EL84 amp" which technically isn't correct

If the amp is putting out 15 watts with Yellow Jackets, then it probably isn't Class A. An EL84 amp running in true class A probably wouldn't put out more than 10watts maximum given that an EL84 is a 12w maximum dissipation tube in class A. Class A is only 40% efficient, so for two you're looking at 9.6w. Also, the anode voltage would have to be 300v or less. Someday I'll have to get some Yellow Jackets and measure some of the voltages to see what they are actually doing in the circuit.

tung

 

[kipper]

You seem really deadset on getting a speaker, but it sounds like your intent is acutally tamming this amp for bedroom use?

Well I was interested in changing the speaker because I'd heard that this can improve the sound and I'd read good reports of the V30...ultimately though, yes, it would be good if I could ditch the Z Air Brake attenuator (or at the very least not have to use it in anger like I do now), very good product though it is.

And if the speaker is going to make it louder then you dont want the speaker...even if its going to sound better.

Fair comment. Although if I change tubes as well, it might make sense to change the speaker...or does it?

So Im gonna try and sway you another dirrection entirely...get new tubes instead.

If youve got OEM powertubes, some new Winged C powertubes will get rid of that brittle/crackly tone and will add more sparkle and shimmer.
And if you get new preamp tubes, Id suggest getting two 12AT7's(for V1 and V3) and one 12AX7(for V2)(I like JJ's for the preamp)...these will tame your amp for bedroom level AND will shape your tone in a more desireable dirrection.

How would switching to 12AT7 in V1 and V3 help tame the volume? Would I not be better off replacing the 6L6 tubes with THD Yellow Jackets, and take the amp into Fender/AC15 hybrid territory, both sound and volume-wise?

I suspect no matter what I do I'll have to keep using the Air Brake...if I didn't have to use it all that would be good, but at the very least it would be nice to not have to attenuate so much when playing at home.

Also, if I changed the preamp tubes in the manner you suggest, what if I also changed the power tubes to THD Yellow Jackets? Or would it best to only do one of these mods, not both?

 

[Jimi75]

My 4x12 is equipped with Celestion G12 Century Vintage. Great speaker with tons of clarity.

 

[ShortBuSX]

Not picking on you ShortBuSX, but I would recommend 5751s or 12AY7/6072s over the 12AT7. Why? The 5751 and 12AY7/6072 are lower gain versions of the 12AX7, the 12AT7 is not. The 12AT7 has different operating specs. One things that concerns me about putting a 12AT7 into a modern-production Fender amp is that they almost surely use 1/4 rated resistors. The 12AT7 is capable of drawing more current than a 12AX7 and the resistor values are all wrong for the 12AT7.

If you've done this and it works for you, then more power to you. But knowing what I know, I personally wouldn't do it without upgrading the appropriate resistors with 1/2W types with values more in line with what a 12AT7 would like to "see." FWIW.

I cant say that I really understand what youre saying, I dont know ohms law nor can I really read a schematic...I got my info from http://studentweb.eku.edu/justin_holton/tooloud.html#lowergain among other sources, but according to Justin's site:

Putting in Lower Gain Preamp Tubes
This is one of the most popular, non-destructive mods for Hot Rods. The HRDx uses three dual-triode 12AX7s for its preamp section and phase inverter. The 12AX7 is considered to have an gain factor of 100%. Its sister triodes, the 12AT7 and 12AY7, have much lower gain factors and can be freely exchanged in place of the 12AX7s. If you have trouble understanding what that means then click here. The Tube Store does a great job explaining this, and includes a neat interactive graphic to help you learn.

Replacing several preamp tubes with their lower gain counterparts will obviously have more of an effect on the volume than only replacing one. Many people describe the lower gain tubes as having more of a "bluesy" sound. Personally, I like the 12AT7 in V3 with 12AX7s in the other two spots. I know many people who don't like how this sounds in their HRD. All of it really depends on the speaker that's in your HRD, and the sound of the instrument being played. The most popular replacement seems to be a lower gain tube in V2, which is part of the Drive channel. To find out which tubes do what, check out my preamp FAQ. To read more about the sonic differences between tubes check out KCA NOS Tubes and The Tube Store.

Further more, non of the tubes sites make any such statements, that I cant use a 12AT7, most everything says they are interchangeable.
and according to this a 12AT7 is in fact a lower gain tube...so youve lost me, and if I didnt know better Id think you were talking about EL84s or something, but Im sure theres something you know that I dont, so I'll wait for the explanation.
But then again I do use 12AT7's as well as ECC81 in my amp and it works quite well.

 

[ShortBuSX]

How would switching to 12AT7 in V1 and V3 help tame the volume?

A lower gain tube in stage one(V1) will reduce the volume of the clean channel.
If you use a lower gain tube in V3 with decrease the overall volume of both channels, itll get rid of alot of the boom-iness...itll also give it more of a vintage-y tone.
If youre not happy with the drive channels try a lower gain tube there. I think that most people who dont appreciate the drive channels on these amps have never tried lower gain preamp tubes in V2, its so much more pleasant and useable now.

Currently Im using a JJ ECC81 in V1, a JAN 5751 for V2 and a EH 12AY7 for V3, but I also have a JAN 12AT7WC for V3 when not at home, like playing with a band where Id need more volume without sounding too thin.

I think youll always want or need to use that attenuator now that you have it...I dont have one and I make due without, I cant justify the expense as of yet, Id rather buy another amp...but I do get good use out of my volume box.

I dont have any experience with Yellow Jackets, 6V6 or speaker upgrades...but I couldnt imagine replacing the speaker(or speakers 4x10 in my case) without first trying new power and preamp tubes.

 

[tunghaichuan]

I cant say that I really understand what youre saying, I dont know ohms law nor can I really read a schematic...I got my info from http://studentweb.eku.edu/justin_holton/tooloud.html#lowergain among other sources, but according to Justin's site:

In a nutshell, what I'm saying is that a 12AT7 is not a lower gain 12AX7, they have different electrical characteristics and require different cathode and anode resistor values to work properly in their respective circuits. "Properly" being a relative term. We are talking guitar amps here, so the 12AT7 is close enough for rock and roll. The 5751 and 12AY7 are close enough in electrical characteristics to be considered lower gain 12AX7s.

Further more, non of the tubes sites make any such statements, that I cant use a 12AT7, most everything says they are interchangeable.
and according to this a 12AT7 is in fact a lower gain tube...so youve lost me, and if I didnt know better Id think you were talking about EL84s or something, but Im sure theres something you know that I dont, so I'll wait for the explanation.
But then again I do use 12AT7's as well as ECC81 in my amp and it works quite well.

Like I said in my previous post, if the 12AT7 works for you and doesn't cause any problems, great.

What I'm trying to reinforce here is that just because a 12AX7 and a 12AT7 look alike and share the same pinout, doesn't mean that the 12AT7 is a lower gain version of the 12AX7. The Tube Store is wrong in that regard. What I'm getting at is that you can't plug a 12AT7 into a 12AX7 socket and expect it to behave like a lower gain 12AX7. A 12AT7 only has a gain factor of 60 when put into a circuit with cathode and anode resistor values that are optimized for it.

The Tube Store also says this:

Before you discover the new possibilities in your amp, let us give a disclaimer. Your amp was originally designed for a certain type, and although tube amps are often forgiving, it may not have a tone that you like with a different tube type. For instance, changing the tube type doesn't only change the gain factor; there are other variables as well and your amp may have a circuit that is more particular than others. As a general rule, the substitutions we describe here should work well but there are exceptions and we don't warranty any problems that result from trying mismatched tube types. For the best results, find other people on the net who have experience swapping tubes with the amp you use.

Call me cynical, but the Tube Store sells tubes, it is in their best interest to promote this kind of information. But notice the disclaimer: if you screw up your amp mismatching types (not that you will) they are not responsible.

Having said that, it is a good idea to become familiar with tube data sheets. Here is an excellent source:

http://www.nj7p.org/Tube.php

A few more:

http://tdsl.duncanamps.com/

http://frank.pocnet.net/

The Tube Store is right in saying that tube amp circuits are forgiving. But a little knowledge is a dangerous thing. Why take a chance?

I guess all I'm really trying to say is educate yourself and don't take what Internet sites say on faith.

tung

 

[ShortBuSX]

I guess all I'm really trying to say is educate yourself and don't take what Internet sites say on faith.

Yeah, thats why I put all that out there...I figured youd provide links, thanks!:AOK:

[edit]But of the first link you posted, I look up 12AT7 and 12AX7 and the heater current and voltage are the same...what points am I supposed to be looking at, what should I be aware of???
I guess I just dont understand what I should be cautious of?
Seems quite common to use 12AT7s in these amps :shrug:

 

[tunghaichuan]

Yeah, thats why I put all that out there...I figured youd provide links, thanks!:AOK:

[edit]But of the first link you posted, I look up 12AT7 and 12AX7 and the heater current and voltage are the same...what points am I supposed to be looking at, what should I be aware of???
I guess I just dont understand what I should be cautious of?
Seems quite common to use 12AT7s in these amps :shrug:

Look at the characteristics and typical operation tables and the maximum ratings:
12AX7:
Maximum Ratings (Design Center Values)
Each TriodePlate Voltage: 330 V
Plate Dissipation: 1.2 W

Characteristics and Typical Operation
Class A AmplifierPlate Voltage: 250 V
Grid No. 1 Voltage: -2 V
Amplification Factor: 100
Plate Resistance (approx): 62.5K Ω
Transconductance: 1600 µ
Plate Current: 1.2 mA

12AT7:
Maximum Ratings (Design Center Values)
Each TriodePlate Voltage: 300 V
Plate Dissipation: 2.5 W

Characteristics and Typical Operation
Class A AmplifierPlate Voltage: 250 V
Grid No. 1 Voltage Derived from Cathode Bias Resistor: 200 Ω
Amplification Factor: 60
Plate Resistance (approx): 10/9K Ω
Transconductance: 5500 µ
Plate Current: 10 mA

The 12AT7 has about one fifth of the plate resistance of a 12AX7 and can dissipate twice the wattage.

Now look at the 12AU7:

Maximum Ratings (Design Center Values)
Triodes 1 & 2
Plate Voltage: 300 V
Plate Dissipation: 2.75 W

Characteristics and Typical Operation
Class A Amplifier
Plate Voltage: 250 V
Grid No. 1 Voltage: -8.5 V
Amplification Factor: 17
Plate Resistance (approx): 7.7K Ω
Transconductance: 2200 µ
Plate Current: 10.5 mA

If the 12AT7 and 12AU7 were lower gain versions of the 12AX7, the only thing that would change would be the amplification factor.

tung

 

[ShortBuSX]

Well thats too bad, I really like the 12AT7 and ECC81 in this amp...moreso than the 5751:thwap:

Thanks for the warning, but I think Im gonna hafta continue to use em regardless.

 

[tunghaichuan]

Well thats too bad, I really like the 12AT7 and ECC81 in this amp...moreso than the 5751:thwap:

Thanks for the warning, but I think Im gonna hafta continue to use em regardless.

Like I said, the 12AT7 is close enough for rock and roll. If it hasn't caused you any problems, then I wouldn't worry. One of the reasons I posted all that technical stuff was so that you could make an informed decision about your amp.

tung

 

[ShortBuSX]

Tung, do you think you might be able to advise me on this Master Volume issue?
Its the Master Volume thats the touchy one everyone talks about modding on these amps, the amp comes with a 100k linear taper...now heres where it gets confusing. Is 100k the right value for an audio taper? There is no "drop in" pot available in the 100k audio range, but you can find 250k, 500k and 1meg audio tapers that are.
After reading http://studentweb.eku.edu/justin_holton/jvmods.html#master over and over again, Im even more confused than when I started. BTW the schematic links are also located on that page(Ive got a Deville if that makes a difference)...I cant read schematic too well, and I couldnt begin to second guess a schematic cause I dont know all the formulas...but what value pot should I use to replace the mater volume on this amp? This info would be very much appreciated!

 

[tunghaichuan]

It looks to me like R26 is the right value as it is driving an op amp, which wants to see a lower value than a tube would in the same position.

There are two things you could try: replace R26 with a 250k audio taper pot. This is more than double the resistance of the original, though. I'm not sure what doubling the resistance would do to the op amp.

The other thing you could do is get a dual ganged 250k audio taper pot and wire the lugs together: 1 to 1, 2 to 2, 3 to 3. This would put the two pots in parallel and would put the resistance to 125k, which is very close to 100k. The only downside is that it maybe hard to shoehorn this new pot into the circuit as it is twice as thick due to the extra pot.

tung

Tung, do you think you might be able to advise me on this Master Volume issue?
Its the Master Volume thats the touchy one everyone talks about modding on these amps, the amp comes with a 100k linear taper...now heres where it gets confusing. Is 100k the right value for an audio taper? There is no "drop in" pot available in the 100k audio range, but you can find 250k, 500k and 1meg audio tapers that are.
After reading http://studentweb.eku.edu/justin_holton/jvmods.html#master over and over again, Im even more confused than when I started. BTW the schematic links are also located on that page(Ive got a Deville if that makes a difference)...I cant read schematic too well, and I couldnt begin to second guess a schematic cause I dont know all the formulas...but what value pot should I use to replace the mater volume on this amp? This info would be very much appreciated!

 

[ShortBuSX]

Hey Tung, lemme ask you...is there any easy way of turning this linear taper to an audio taper? The reason I ask is it seem rather easy to turn a normal pot into a "no load"....could I mod this existing pot to an audio taper???

 

[tunghaichuan]

Hey Tung, lemme ask you...is there any easy way of turning this linear taper to an audio taper? The reason I ask is it seem rather easy to turn a normal pot into a "no load"....could I mod this existing pot to an audio taper???

I can't think of any. A pot is just a variable resistor. The two outer lugs are connected to a resistive track on the inside of the pot. The center lug is connected to the wiper the rides on the track. The way the track is deposited determines whether or not it is audio or linear taper. Audio taper pots have most of the resistance bunched up on one end to simulate the logrhythmic curve that the human ear has. A linear taper pot has the resistance distributed evenly along the track.

tung