73' Deluxe Reverb OT, 16 ohm speaker better than 8?

[BrownsBrick]

Hello, this is my first new thread,

I own a 73 Deluxe Reverb, BF'd, with added Neg Feedback control pot and Mid Pot added in back where the external speaker out and ground switch used to be. I have been thinking of reversing the Mid pot mod to regain access to the external speaker jack to run a cabinet out. Is it fact or fiction that Deluxe OT's can't really handle the 4 ohm load of the 8 ohm speaker and a matching 8 ohm out cabinet, and would the distortion charactor get less flubby at higher volumes if I switched out the 8 ohm speaker for a 16 in my Deluxe?

Thanks a bunch

[telbert twang]

I am curious on this as well . I have read several places about the DR OT being better suited for 16-ohm speaker instead of the original 8-ohm, to get less flubbyness while cranked.

Here is also a link about the similar : http://www.thegearpage.net/board/sho...d.php?t=139966

Any comments or suggestions from amp-wise people ?

[Wally]

IMho, the DR like most other FEnders will tolerate a 100% mismatch either way. Most folks hold that a properly matched load is the best scenario. When a mismatch is run, I believe that the 4 ohm load would be better than the 16 ohm. With all other considerations such as efficiency and frequency range of the speaker considered equal, the 16 ohm load on that 8 ohm OT will decrease output and darken the tone a bit. Whether one likes that or not is a personal thing.
IF I were going to run an extension cab full time with a DR, I might seriously consider running identical 16 ohm speakers in the amp and the ext cab for a total load of the 8 ohms that would match the designed load requirement of the OT.
The easiest way to reduce 'flubbiness' in a FEnder reverb amp when cranked is to but the bass freqs with the BAss tone pot, ime.

[Natstrat79]

Originally Posted by Wally

The easiest way to reduce 'flubbiness' in a FEnder reverb amp when cranked is to but the bass freqs with the BAss tone pot, ime.

That would be the most logical thing to do . If that still doesn't do it for you though the coupling capacitors between the phase inverter and power tubes could be changed from .1uf to .047uf or even .022uf.

[Wally]

Originally Posted by Natstrat79

That would be the most logical thing to do . If that still doesn't do it for you though the coupling capacitors between the phase inverter and power tubes could be changed from .1uf to .047uf or even .022uf.

For my money, I start looking at the preamp. The .1 bass cap and the .047 can be changed to smaller values and gets those freqs under control long before they become a problem. Natstrat's suggestions are valuable, too; I jsut like t o address the probelm in the early stages.
When looking at the output section, I consider bumping up the filtering capacity at that first section of filtering.

[telbert twang]

Its not a big issue for me, just curiosity. I love my SFDR very much - imho most optimal package with monster tone. Yes, the bass turndown decreases it (the flubb-factor) , but I still guess that the DR seems just kinda to push the speaker much more agressively, comparing to any other amp I´ve seen or tried.

[BrownsBrick]

Originally Posted by telbert twang

Its not a big issue for me, just curiosity. I love my SFDR very much - imho most optimal package with monster tone. Yes, the bass turndown decreases it (the flubb-factor) , but I still guess that the DR seems just kinda to push the speaker much more agressively, comparing to any other amp I´ve seen or tried.

Agreed; A deluxe has a lot of wild peaks coupled with a slower onset of distortion due to the tube rectifier that can drive even a 60 watt speaker nuts. I take that into consideration, but a darker sound from the ohm mismatch may be a good experiment to get what i'm looking for depending on the speaker. Either that or just get an Electro-Voice

[Wally]

Originally Posted by BrownsBrick

Agreed; A deluxe has a lot of wild peaks coupled with a slower onset of distortion due to the tube rectifier that can drive even a 60 watt speaker nuts. I take that into consideration, but a darker sound from the ohm mismatch may be a good experiment to get what i'm looking for depending on the speaker. Either that or just get an Electro-Voice

Brownsbrick, could you elaborate on your claim that a tube rectifier delays the onset of distortion??

[BrownsBrick]

Hey Wally; I'll give an example; A Vox AC30 running in Class A has a very "smooth" and quick onset of distortion; no sag either from the GZ34. Im sorry i didnt elaborate on that; as this is an example of a rectifier that doesnt sag.

[Wally]

Browns, I will agree that the GZ344 has the least amount of sag of all tube rectifiers. That said, it is a bit different than a SS rectifier. I am going to think that with a SS recctifier, that Vox will exhibit a bit of a sharper edge to the distortion than with a GZ34.
The cathode biasing of the AC30 has a lot to do with the smoothness of that distortion, also, imho. Class A? Cathode biasing alone does not a Class A operation make. IT is true push/pull AB.

[BrownsBrick]

I know they run in true A/B at higher volumes...wow i better not perpetuate this thread has gone way off subject; well; anyways I ordered a reconed JBL D120-F at 8 ohms and a Celestion Gold so i'll see where they take me

[Wally]

It's your thread, Brownsbrick. You can take it anywhere you want to go with it!
Have a good one.

[BrownsBrick]

I was on the phone with my amp tech who was puzzled by this as well. He then called mercury magnetics and they confirmed that on SF Deluxe Reverb OT's there is no tap to go to 4 ohms when using an extention cab, therefor running 4 ohms and an 8 ohm tranny maxed out. This apparently is a no no.

I had him revert the mid to fixed and added no extention jack at all for safety in case i decide i want to screw things up (it has happened!). Mercury also said a 16 ohm speaker would sound darker and doesnt loose the power expected, adding a bit more clean headroom.

I have 4 speakers now for my Deluxe Reverb to try, all 8 ohms;

Weber 12f150 (which is what ive always had in it)
Orange Frame JBL d120f (reconed with hemp by Tone Tubby like Santana uses on his to reduce the ice picks, 125 dollar score)
Grey Frame JBL d120f reconed with a generic JBL kit
Celestion Alnico Gold

I will post a new thread with info on my findings, but any comments on these speakers is greatly appreciated.

[Singin' Dave]

Originally Posted by BrownsBrick

I have 4 speakers now for my Deluxe Reverb to try, all 8 ohms;

Weber 12f150 (which is what ive always had in it)
Orange Frame JBL d120f (reconed with hemp by Tone Tubby like Santana uses on his to reduce the ice picks, 125 dollar score)
Grey Frame JBL d120f reconed with a generic JBL kit
Celestion Alnico Gold

I will post a new thread with info on my findings, but any comments on these speakers is greatly appreciated.

All excellent speakers. I have a '73 DR myself which is currently loaded with a Celestion Gold. Love the combination - there is a 3D like roundness to the tone with this speaker and I find it breaks up a little sweeter than the 12F150 I had in it for a while (which I really liked too!). For straight ahead punchy cleans, I think I prefer the Weber, but all around, this Gold really does it for me in this amp.

Although I do have a JBL D130F in a Showman 15 cab, I can't really comment on how your D120F's will sound, but I bet they would kill for really nice cleans. I'd probably try that hemp cone one first.

Strong recommendation to record the amp with different speakers at the same settings. Sometimes it's hard when you are playing to sit back and really listen to the nuances of each speaker.

Here's my amp (lifetime keeper)

[Wally]

It is not a 'no-no' to run a 4 ohm load on an original 8 ohm OT in a DR. IT matters not whether one runs the in-cab 8 ohm in parallel with an external 8 ohm cab plugged into the 'text spkr' jack or whether one runs one single 4 ohm load on the primary or Main Spkr jack.
It is true that the DR's OT has only one tap, and that tap is rated for an 8 ohm load. However, the design of the circuit and the OT allow for a 100% mismatch in either direction. So, a DR will handle a 4 ohm load, an 8 ohm load or a 16 ohm load. MOst people agree that optimum performance is achieved with a load that is matched to the OT's rating, but too many fender amps have been run with 100% mismatches in either direction for too many years for this not to be common knowledge. Someone is misunderstanding something in the process of shared information between you, the tech and MM. Leo and Co. started providing the ext spkr jack on these amps that allowed these mismatches many years ago. I have seen TR's run 8 ohm loads for decades. I have seen 8 and 4 ohm Fender OT's handle the provided for ext spkr parallel loads with no bad results.
IF an amp has a multitap OT, then I always prefer to match the load to the tap. With these vintage Fenders, there is no fear that a properly running amp will suffer undue harm from 'proper' mismatches. Now, if you put a 16 ohm load on a 4 ohm transformer, you are skating on thin ice and the sonics suffer drastically, ime. And...I would never run a 2 ohm load on a DR 8 ohm OT.

[BrownsBrick]

Originally Posted by Singin' Dave

All excellent speakers. I have a '73 DR myself which is currently loaded with a Celestion Gold. Love the combination - there is a 3D like roundness to the tone with this speaker and I find it breaks up a little sweeter than the 12F150 I had in it for a while (which I really liked too!). For straight ahead punchy cleans, I think I prefer the Weber, but all around, this Gold really does it for me in this amp.

Although I do have a JBL D130F in a Showman 15 cab, I can't really comment on how your D120F's will sound, but I bet they would kill for really nice cleans. I'd probably try that hemp cone one first.

Strong recommendation to record the amp with different speakers at the same settings. Sometimes it's hard when you are playing to sit back and really listen to the nuances of each speaker.

Here's my amp (lifetime keeper)

I love my weber 12f150, which is why im getting a 1x12 baffle for my princeton to drop it in and spare the stock jensen some more pounding.
But which one is LOUDER! (weber 12f150 or the celestion gold)

[BrownsBrick]

Originally Posted by Wally

It is not a 'no-no' to run a 4 ohm load on an original 8 ohm OT in a DR. IT matters not whether one runs the in-cab 8 ohm in parallel with an external 8 ohm cab plugged into the 'text spkr' jack or whether one runs one single 4 ohm load on the primary or Main Spkr jack.
It is true that the DR's OT has only one tap, and that tap is rated for an 8 ohm load. However, the design of the circuit and the OT allow for a 100% mismatch in either direction. So, a DR will handle a 4 ohm load, an 8 ohm load or a 16 ohm load. MOst people agree that optimum performance is achieved with a load that is matched to the OT's rating, but too many fender amps have been run with 100% mismatches in either direction for too many years for this not to be common knowledge. Someone is misunderstanding something in the process of shared information between you, the tech and MM. Leo and Co. started providing the ext spkr jack on these amps that allowed these mismatches many years ago. I have seen TR's run 8 ohm loads for decades. I have seen 8 and 4 ohm Fender OT's handle the provided for ext spkr parallel loads with no bad results.
IF an amp has a multitap OT, then I always prefer to match the load to the tap. With these vintage Fenders, there is no fear that a properly running amp will suffer undue harm from 'proper' mismatches. Now, if you put a 16 ohm load on a 4 ohm transformer, you are skating on thin ice and the sonics suffer drastically, ime. And...I would never run a 2 ohm load on a DR 8 ohm OT.

Appreciate the help, Wally, you sure know your stuff!

[Wally]

Bricks....I keep trying to learn....it is all I can do.