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Topic: DRRI....how do I maximize the headroom? |
Steve Leal
From:
Orange CA, USA
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Posted 14 Sep 2004 10:51 pm |
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I recently purchased a 65 Deluxe Reverb Reissue (DRRI) amplifier. I replaced the stock Jenson speaker with an EVM 12L speaker which helped a lot. I have not touched the stock groove tubes yet. I took it out last weekend for it's first test run at a gig (playing E9th steel). I was very happy with the tone of the amp, but to compete with the band, I turned the volume up to 7-8ish. With my volume pedal pushed all the way down, the amp distorted too much for my preference. The volume was "loud" enough, but it just broke up too much.
My question is this: What can I do to "maximize" this amp's headroom?
My guitar friend has the same amp, and replaced the 6V6GTs with 6L6s and rebiased. I am planning on trying this out along with changing the tube rectifier to a weber ss copper cap rectifier (WZ34). If I do this, what should the amp's bias setting be changed to? (Of course, I will have a professional do this for me) Besides the sound change, could this tube change damage my amp? If I decide to keep using 6V6s, can I still use the weber WZ34? What pre-amp tubes should I replace to maximize headroom?
I have been digging around the forum for the last week looking for these answers, but I would like to gather DRRI owners' and experts' thoughts and opinions here. Thank you so much! |
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Jerry Clardy
From:
El Paso, Texas, USA * R.I.P.
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Posted 14 Sep 2004 11:23 pm
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| Steve - The Groove Tubes have a hardness number. The higher the number the later the distortion. 10 would have the most headroom. Have you checked for this? [This message was edited by Jerry Clardy on 15 September 2004 at 12:56 AM.] |
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Chuck Fisher
From:
Santa Cruz, California, USA * R.I.P.
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Posted 15 Sep 2004 10:03 am
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1) switching to 6l6 will most likely create an overload it the transformers (both output and power transformers) that will damage the hardware.
2) you can make the amp respond to peaks better by using a plug-in solid state rectifier instead of the tube, or by soldering diodes into the circuit eliminating the rectifier tube. (easy to change back)
3) higher mfd rating on filter capacitors will clean things up a bit by upping available peak current.
I have done these on a deluxe reverb and got a reliable outcome that cut through the band a bit better.
A jbl 120 F might be a db or 2 louder although I'm not that up on the EVM
performance |
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Steve Leal
From:
Orange CA, USA
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Posted 15 Sep 2004 10:48 am
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Jerry...I took a look at the 6V6GT groove tubes. It looks as though the "groove tube logo (white writing) was printed over the original writing which says "electro harmonex and appears to have the number 11". Not sure if that is what you are refering to.
Chuck...Thanks for the warning. I have ordered a weber copper cap solid state rectifier, but I have read postings on this forum and the fender forum saying not to use a solid state rectifier with 6V6s. I am confused now. |
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Bobby Lee
From:
Cloverdale, California, USA
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Posted 15 Sep 2004 10:59 am
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Running two speakers in parallel will reduce the load to 4 ohms, producing more power safely. Or you could switch to a single 4 ohm speaker. Anything below 4 ohms would run the risk of overheating the amp.
As Chuck said, a solid state rectifier helps, too. You can get these installed in a tube socket, as a direct replacement for the rectifier tube.
I don't understand the reasoning behind any warnings about 6V6s and diode rectifiers. Some rock guitar players really like the audible sag that the rectifier tube gives you, but steel has different requirements. My 40 watt Boogie (with EL84 power tubes) has both kinds. I rarely find the tube rectifier useful, even in low volume situations. The solid state diodes increase headroom and make the amp more responsive.
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 Bobby Lee - email: quasar@b0b.com - gigs - CDs, Open Hearts
Sierra Session SD-12 (Ext E9), Williams D-12 Crossover
Sierra Laptop 8 (E6add9), Fender Stringmaster (E13, C6, A6) |
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Thomas Bancroft
From:
Matawan, New Jersey, USA
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Posted 15 Sep 2004 11:14 am
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Steve,
Billy Penn of Penn Instrument Co., who Blackfaced my 72 Super Reverb, told me that the Copper Cap sags just like the tube rectifier which is why he likes to use them. 12AT7's in the preamp section should clean up the sound.
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Mullen D-10, Melobar Rattler, Nashville 1000, Alesis Midiverb, Too Many Guitars! |
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Chuck Fisher
From:
Santa Cruz, California, USA * R.I.P.
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Posted 15 Sep 2004 11:39 am
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I am not familiar with the coppertop plug-in rectifier, but non-sagging rectifiers help, and the 5v filament not being drawn makes the power transformer run a bit cooler. (perhaps this coppertop unit is designed to sag?)
Running a second speaker, or disconnecting and hooking up a 4-12 box is going to be the biggest boost, not because the lower impedience (ohms) , but because the greatly increased surface area of speaker-cone, probably resulting in more boost than doubling the wattage. |
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Steve Leal
From:
Orange CA, USA
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Brad Sarno
From:
St. Louis, MO USA
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Posted 15 Sep 2004 2:21 pm
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Keep in mind that 24 watts is 24 watts. You can improve quickness and punch with the solid state rectifier, but it's still 24 watts. The easiest way to get MUCH louder and cleaner is to use a more efficient speaker. The JBL D120 is incredibly efficient, thus much louder. Putting in 6L6's and rebiasing is just asking for trouble. The transformers don't want to do it. A Deluxe is a great amp, but if you run out of clean headroom, it's time for a more powerful amp IMHO. I believe that the JBL is more efficient than the EV by a longshot, but it's been a while so I can't confirm that. I love the Fender Deluxe Reverb amp!!!
Brad Sarno |
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Jerry Clardy
From:
El Paso, Texas, USA * R.I.P.
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Posted 15 Sep 2004 4:12 pm
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Steve - I wasn't aware of the 11. The 1-10 rating I'm talking about is on the Groove Tube site at http://www.groovetubes.com/products.cfm Item 2.
I think Brad probably has the handle on your problem, though.
[This message was edited by Jerry Clardy on 15 September 2004 at 07:33 PM.] |
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Jim Peters
From:
St. Louis, Missouri, USA, R.I.P.
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Posted 15 Sep 2004 7:16 pm
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| Steve, you should rebias your tubes if you put a solid state rec. in your deluxe, the voltages change quite a bit. You will gain more headroom, but not a lot. The speaker change would help also, but you're still slammin those tubes with a big damn pickup. The Deluxe is made to breakup early, that's why we guitarists love it! Keep that amp, get a Nashville 112, I did, and now I can love them both! JimP |
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Steve Leal
From:
Orange CA, USA
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Posted 16 Sep 2004 1:13 am
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JimP...I am really happy with my DRRI for both steel and guitar. I just need a tad more headroom to compete with the loudest band I play with. It is almost there. I have already replaced the speaker with the EVM 12L.
I think the 6L6s, the weber ss rectifier, and possibly changing some of the preamp tubes will make it just perfect (and of course rebiasing). Does anyone know the bias settings I should tell my tech to use for these changes? Also, what brand of 6L6 tubes would be the best to use? |
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John Daugherty
From:
Rolla, Missouri, USA
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Posted 16 Sep 2004 4:40 am
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You WILL get a power increase with the solid state rectifier because the B+ voltage will be higher than with the rectifier tube.
I don't have a schematic for your amp so I can't tell you if it has a bypass capacitor on the cathodes of the 6V6s. If it has an electrolytic cap connected between pin 8 and ground, you can replace it with one of higher value. Use a value about 4 times the original value(in my experienced opinion).
I have done this to old tube amps and got more power and cleaner sound.....JD |
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Donny Hinson
From:
Glen Burnie, Md. U.S.A.
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Posted 17 Sep 2004 5:00 pm
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| I believe that the JBL is more efficient than the EV by a longshot |
I used to run a D130 in my blackface Twin Reverb, and the tone was great, but the power I needed just wasn't there. The old D130 was pretty good in it's day, but it's volume output was just a little more than half that of the EV SRO-15 that I replaced it with. I compared the speakers both in the cabinet, and just sitting on the bench, side-by side. (Each was 8 ohms and 15".) The tone with the JBL was a little sweeter and rounder, but the SRO had it all over the D130 when it came to efficiency. As I had had many problems with frying the voice-coils and tearing the surrounds with JBL's, I switched to the SRO...and never looked back. I still think the SRO is one of the best speakers for steel ever designed.
If you ever have the opportunity, just try the side-by-side test yourself. I think you, too, will be quite surprised! 
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Sorry Steve, but unless you're always miking the DRRI, I feel it's a poor choice for pedal steel.  I think the easiest and cheapest way for you to dramatically raise your headroom would be to sell the DRRI, and get a Twin Reverb. Either the 100-watt version, or (preferably) the 135-watt version will put even a modded DRRI to shame in the "headroom" department. |
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James Morehead
From:
Prague, Oklahoma, USA - R.I.P.
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Posted 17 Sep 2004 5:29 pm
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| I'm with Donny. I think the EV's can handle MUCH more power. EV's are probably the cleanest speaker you can find.(I'm refering to the older speakers--I have not tried the new models out now). I too, feel the JBL's are a sweeter speaker, but can't handle as much power as the EV's. I had a pair of EV 12L's in my Super Twin Reverb, and at 180 watts rms, they stayed clean WAY past "bleeding ears". Ev 12L's and 15L's are 200 watt speakers. At least that's what is stamped on mine. Currently, I'm using my JBL's---TONE HEAVEN!! But I am real careful with them. I don't think your Deluxe will out work your EV 12L. If you don't have enough headroom, it ain't the speaker. Just my opinion. [This message was edited by James Morehead on 17 September 2004 at 06:40 PM.] |
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Steve Leal
From:
Orange CA, USA
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Posted 26 Sep 2004 7:59 pm
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Well guys, I bought me a pair of GT6L6GE tubes and the weber copper cap solid state rectifier tube. On Friday, I took them and the amp to Paul Morte (the best amp serviceman in my area that I know of). He called me back a few hours later and told me the amp was ready to be picked up. He installed the GT6L6GE power tubes, and he tried the weber rectifier, but he told me it didn't sound good and put the original 5AR4 rectifier tube back in. He said that the 6L6s increased the power/headroom slightly, but not an increadible amount. He did say that the 6L6s sounded very nice though.
I will pick the amp up tomorrow and try it out. I was a bit disappointed that he didn't want to use the weber rectifier that I have heard so many good things about on the steel guitar forum. Also I paid $26 for it for nothing.
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