Author Topic: Question about preamp gain (Read 249 times)

benson_murrensun · « **on:** March 09, 2011, 11:08:10 AM »

I have an Avalon U5 DI/Preamp and am considering using it as a preamp, sending my bass' signal directly from that to a power amp. Has anybody here done this? Avalon's specs say this unit has up to 30 db of gain. Is that enough to drive a power amp to it's potential? If not, what amount of gain is preferable? Thanks in advance for your input....

JimmyJ · « **Reply #1 on:** March 09, 2011, 11:21:18 AM »

Ben,
That should be plenty of gain and would probably sound amazing. Plug it in and try it!
Jimmy J

sonicus · « **Reply #2 on:** March 09, 2011, 11:58:40 AM »

I think Jimmy J is right. In fact I believe I remember have seen and heard it done. Here are the specs;
http://www.avalondesign.com/instrudi.html

benson_murrensun · « **Reply #3 on:** March 09, 2011, 12:08:08 PM »

Thanks, gentlemen. I know Avalon says you can do it, and I just did some research on other forums in which it is indicated that it works well. I was just a little concerned about being able to get my passive basses up to a good level with this proposed setup.
Just for grins, does anybody know what the max. gain on an F-1X is? I have one of those, too, and it may be helpful to compare the specs.
Jimmy, I will plug it in and try it, but I'm at the office now and that will have to wait for this evening, so I'm just doing some groundwork (goofing off) before quitting time.... ;-)

bigredbass · « **Reply #4 on:** March 09, 2011, 11:21:31 PM »

Avalons are VERY nice gear. If you're not 'knob-happy', the U5's are very straightforward. I do like simple, as I believe simplicity is elegant.
And Avalons are certainly elegant.

It will certainly drive a power amp, and be good enough to hear the difference in power amps, something a lot of gear can't do. Congrats !

J o e y

benson_murrensun · « **Reply #5 on:** March 10, 2011, 09:50:56 AM »

Thanks, Joey. I've had the Avalon for a while, but haven't been using it, as I have had no need for a DI lately. The sound quality is beyond excellent; In the past I have used it as a headphone amp and with my Sony MDR-7506 cans I can tell the difference between instrument cables, it's that good. I think it's time to resurrect it, this time as an instrument preamp...

oddmetersam · « **Reply #6 on:** March 11, 2011, 12:52:39 AM »

Ben, please let us know how this sounds to you as an instrument preamp. I love my F1-X but I'm always looking to try new stuff.
-Sam

benson_murrensun · « **Reply #7 on:** March 11, 2011, 09:17:40 AM »

Will do, Sam. It might be a week or so before I dig out my QSC power amp, which is buried in storage.... come to think of it, I could just plug the Avalon into the effects return of one of my amp heads... that would be easier. I'll report, though, because inquiring minds want to know!

bigredbass · « **Reply #8 on:** March 11, 2011, 07:42:19 PM »

One day, I shall have an Avalon 737SP !

J o e y

sonicus · « **Reply #9 on:** March 11, 2011, 07:50:15 PM »

Very nice Joey! I can relate to the GAS !
http://www.avalondesign.com/vt737sp.html

sonicus · « **Reply #10 on:** March 11, 2011, 08:10:46 PM »

The D.W.FERN VT-15 makes my Knees weak , Now that is some SERIOUS GAS my friend !
http://www.dwfearn.com/vt-15_channel.html

Unfortunately he discontinued it after I was tantalized by it at an AES convention... lol _____

(Message edited by sonicus on March 11, 2011)

benson_murrensun · « **Reply #11 on:** March 28, 2011, 02:21:59 PM »

Reporting back for those inquiring minds:
I used the following equipment for these tests: SWR Workingman's 400 (older, US-made, pre-Fender), Acme Low B2, home-made bass with mahogany body and neck, rosewood board, EMG passive (Select) pickups, Monster Cables. And the Avalon.
I plugged the bass into the Avalon U5 and then went in to the SWR's effects return. I had to turn the Avalon's boost knob way up to approximate the volume that the SWR produces on it's own. It sounded more defined and refined than when I used the SWR's preamp without the Avalon. I spent a lot of time fiddling with the 6 preset tones settings on the Avalon, but was fine with the tone control out of the circuit - no EQ at all. But I missed the Aural Enhancer that the SWR features... So I plugged the Avalon in to the SWR's Active instrument input, turned the Avalon's boost knob way down, put all the SWR's EQ sliders to the middle position (no boost or cut) and was then able to add some of the Aural Enhancer. This got me the best sound. Just for a reality check I plugged the bass directly into the SWR (with no EQ used) for a while, let my ears get used to it, and then added the Avalon into the equation. The tone was noticeably better when the guitar signal went through the Avalon first.
Next installment: the Avalon directly into a power amp.
And now to check out those other links provided by Sonicus....

(Message edited by Benson_Murrensun on March 28, 2011)

bigredbass · « **Reply #12 on:** March 29, 2011, 12:21:47 AM »

. . . and at that time it will be interesting to see how you face the conundrun that occurs:

There is a BIG difference in real recording/studio/broadcast-quality gear and the typical bass amp/effects pedal world. It's hospital clean versus a warmer, lumpier tone. Trying to meld the two (THAT clean but with some warmth) can be a real challenge for some guys (and I certainly include myself in that list). This is why you see so many of these 'channel strips' with tube front-ends (like the 737SP, which Avalon themselves advise is not as clean or tight-sounding as the U5, but differently warmer) in these digital days.

I shall stay tuned for your impression . . . .

J o e y

benson_murrensun · « **Reply #13 on:** March 29, 2011, 12:42:34 PM »

Point taken, Joey. If my past is any indication, I will probably like a sound that others consider too hospital clean; I go for hi-fi sounding bass gear, and usually don't use tone controls too much, on either the bass or the preamp. The bass I used has lots of mahogany and a rosewood board, so it should have some integral warmth. Next time I will use that same bass plus an active instrument like my Alembic and/or Ritter. And then there are the inherent sonic qualities of the speaker and cabinet... I always thought of the Acmes as hi-fi. But I loaned one to Jack Casady for a show in Boulder and after soundcheck he decided not to use it because it was too heavy-handed. So there you go.

benson_murrensun · « **Reply #14 on:** April 11, 2011, 09:33:14 AM »

Okay, I finally got around to answering my own question... I broke out my (extra-heavy) rack with a QSC RMX2450 and a Yamaha PB-1 preamp. I compared the Yamaha's signal to the Avalon's in A/B tests. The Yamaha had the EQ set flat. The Avalon had the EQ section switched out. The Avalon has plenty of gain to drive the amp loud. The Yamaha, by comparison, has even more gain, but towards the end of volume knob sweep it distorts. So the extra gain it has compared to the Avalon is distorted. The signal is from my bass with EMG passive pickups, so it isn't that hot. I suppose if I sent it an even less hot signal the extra gain on the Yamaha might be useful, or it may just distort anyway. Don't know, don't care. However, the Avalon EQ reduces overall gain, so that should be considered, if it is going to be used. I always thought the Yamaha has a good sound, but compared to the Avalon, it pales. The Avalon is just plain CLEARER (better defined). I bought it a long time ago so I would have a pro D.I. box, but now I see it can be successfully used as a preamp. It's a superior piece of gear.