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Post subject: Re: '68 Deluxe Reverb problems...
Posted: Mon Oct 14, 2013 8:15 pm
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Easy, pull the tube and if the tremolo doesn't work, there's your answer. My understanding is that the new circuitry merely replaces the old "roach" and its surrounding circuitry, and nothing more. As with many things that most engineers do, it's a bit over-done, probably could have been much simpler, which makes it appear to do more than it actually does.

If you want to talk about "all tube", there is really no such thing, as there has to be resistors, capacitors, transformers, switches, etc. I don't see how using a transistor for switching or oscillating is all that different really. Maybe we can start a discussion about the "sound" of the old roach vs the new solid-state. :lol:

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Post subject: Re: '68 Deluxe Reverb problems...
Posted: Mon Oct 14, 2013 10:37 pm
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Shimmy, I like the three-tube phase oscillators in some of the transition brownface amps. Or the tube-only phase oscillator of the Vibro-Champ. These amps seem to have a wider range of control than the opto-roach driven circuits.


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Post subject: Re: '68 Deluxe Reverb problems...
Posted: Mon Oct 14, 2013 11:39 pm
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BMW2002Ti wrote:
Or the tube-only phase oscillator of the Vibro-Champ.


No phase oscillation there -- the trem circuit merely modulates the amplitude of the bias voltage as applied to the 6V6's control grid.

Arjay

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Post subject: Re: '68 Deluxe Reverb problems...
Posted: Tue Oct 15, 2013 1:08 am
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The Vibro-Champ is definitely a weird one. The oscillation of the first half of the vibrato tube, feeds the second half of the vibrato tube, which is a Cathode follower which actually Oscillates (wiggles) the DC voltage on the Cathode of the last gain stage of the preamp, since the output tube is Cathode-biased. So it is wiggling the bias, but of a preamp tube. Weird!

In any event, you can't have any oscillation for the tremolo without some circuitry around the tube to cause the oscillation, whether it is only caps, resistors and a pot, or whether there are a couple of transistors in there also.

My favorite tremolo circuits are the ones that oscillate (wiggle) the output tubes' bias, such as the early Vibrolux or Princeton Reverb (there might be others). Most amps only add oscillation to the signal path (varying the signal path resistance to ground), and it isn't as deep and throbbing as the ones that actually oscillate the output tube bias. The Vibro-Champ is kind of unique in that respect, it is oscillating the Cathode bias of a preamp tube, and sounds pretty darned good.

You know, I have often wondered if the tremolo was one of those accidental discoveries, because normally you don't want oscillation in a circuit. :?:

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Post subject: Re: '68 Deluxe Reverb problems...
Posted: Tue Oct 15, 2013 1:27 am
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shimmilou wrote:
You know, I have often wondered if the tremolo was one of those accidental discoveries, because normally you don't want oscillation in a circuit. :?:


According to sources I've read, Leo did not actually invent the tremolo circuit -- he merely adapted a design that was published in an old radio/hi-fi magazine. It's possible that it was a development for electric organs, perhaps Wurlitzer.

Arjay

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Last edited by Retroverbial on Tue Oct 15, 2013 1:28 am, edited 1 time in total.

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Post subject: Re: '68 Deluxe Reverb problems...
Posted: Tue Oct 15, 2013 1:37 am
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That makes sense. After-all, I understand that's how Leo got started with amps in the first place, by "adapting" others designs. Didn't he adapt a lot from slide guitar amps as well as organ amps?

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Post subject: Re: '68 Deluxe Reverb problems...
Posted: Tue Oct 15, 2013 1:39 am
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I think Leo "borrowed" anything and everything whenever he thought no one was looking.

:lol:

Arjay

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Post subject: Re: '68 Deluxe Reverb problems...
Posted: Tue Oct 15, 2013 1:46 am
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:lol:

Yeah, he did very well in electronics only being a Machinist. :)

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Post subject: Re: '68 Deluxe Reverb problems...
Posted: Tue Oct 15, 2013 2:08 am
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Lawyers. :roll:

Fenders haven't been "all tube" since the early 60's when they switched from tube rectifiers to solid state rectifiers. People were probably up in arms about that too. Did anyone threaten to sue back then? Maybe, I don't know. I have have a real dislike for lawyers who think they see a wrong they have to correct by suing everyone in sight without being asked to do so by the people most affected by the so-called wrong. Lawyers sue and make millions of dollars and the plaintiff gets a free coupon. :lol: :lol: :lol:

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Last edited by bluesky636 on Tue Oct 15, 2013 2:14 am, edited 1 time in total.

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Post subject: Re: '68 Deluxe Reverb problems...
Posted: Tue Oct 15, 2013 2:13 am
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Origins of tremolo in amps (for those that don't trust Wikipedia :lol: :lol: :lol: ):

http://www.premierguitar.com/articles/p ... of-tremolo

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Post subject: Re: '68 Deluxe Reverb problems...
Posted: Tue Oct 15, 2013 7:22 am
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bluesky636 wrote:
Lawyers. :roll:

Fenders haven't been "all tube" since the early 60's when they switched from tube rectifiers to solid state rectifiers. People were probably up in arms about that too. Did anyone threaten to sue back then? Maybe, I don't know. I have have a real dislike for lawyers who think they see a wrong they have to correct by suing everyone in sight without being asked to do so by the people most affected by the so-called wrong. Lawyers sue and make millions of dollars and the plaintiff gets a free coupon. :lol: :lol: :lol:


I agree with you. I'm not a plaintiffs' class action lawyer. But worse cases have been brought and been successful. You are talking about "coupon" settlements. There has been a big effort to stop that kind of thing and make settlements provide more for the claimants.

Anyway....what about a more pressing problem, for guitar players, which is shown in the penumbras of this forum: WHERE CAN ONE GET A QUALITY AMP NOW? I mean....what do I buy? We are seeing complaints that DRRI and this 68 amp and every other amp comes OUT OF THE BOX broken 96% of the time!!!! What gives!!?!!! I'm supposed to buy a Princeton knowing that I have do gerryrig some kind of thing to fix a baffling problem? The tremelo will make a motorboat sound? I mean.... what gives???

Say I have $1,000 and I want a nice amp that sounds good and does not come needing repairs the moment I get it. What do I get?

I see the same complaints about Egnater and Blackstar.

And to spend more....just for more watts and volume that I don't need.

Is it possible to buy a good tube amp today?

I know Arjay advocates real vintage....well, I've looked on ebay.....1965 is getting further and further into the past every day....everything I see there looks really rough if you know what I mean.

What if I'm NOT an electrical engineer or mechanic and I need to be able to buy something that works without me doing something to it. What do I buy?


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Post subject: Re: '68 Deluxe Reverb problems...
Posted: Tue Oct 15, 2013 7:43 am
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Her Wanna wrote:
Are you basically saying that although Fender is advertising these amps as tube amps, they have digital components that essentially are no different than a modeling amp and the tube is literally there for decoration?


Please define what a "tube amp" is, in a legal sense.

I used to have this joke with a friend: whenever we reviewed hifi gear, we put a tube on it and called the sound "tubey".

I think the best is to buy a vintage amp and have it serviced by someone who knows what he's doing. Open the thing up, post pics here, Arjay will tell you what to do. At least that's what I did when I bought my '67 Princeton Reverb. Made me a happy camper.

Her Wanna wrote:
Is it possible to buy a good tube amp today?


Victoria "Victoriette"?

Cheers

David

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Post subject: Re: '68 Deluxe Reverb problems...
Posted: Tue Oct 15, 2013 8:28 am
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bluesky636 wrote:
Origins of tremolo in amps (for those that don't trust Wikipedia :lol: :lol: :lol: ):

http://www.premierguitar.com/articles/p ... of-tremolo


Thanks Bill. Very interesting.

Art


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Post subject: Re: '68 Deluxe Reverb problems...
Posted: Tue Oct 15, 2013 8:37 am
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Amerigo wrote:
Her Wanna wrote:
Are you basically saying that although Fender is advertising these amps as tube amps, they have digital components that essentially are no different than a modeling amp and the tube is literally there for decoration?


Please define what a "tube amp" is, in a legal sense.

I used to have this joke with a friend: whenever we reviewed hifi gear, we put a tube on it and called the sound "tubey".

I think the best is to buy a vintage amp and have it serviced by someone who knows what he's doing. Open the thing up, post pics here, Arjay will tell you what to do. At least that's what I did when I bought my '67 Princeton Reverb. Made me a happy camper.

Her Wanna wrote:
Is it possible to buy a good tube amp today?


Victoria "Victoriette"?

Cheers

David



Thanks. I mean if you look at the DRRI reviews, on guitar center's and other websites....the vast majority of the reviews say super great sound/best amp ever/shoulda bought it sooner/this is the amp to get....BUT a very substantial % say it came with the tremelo or other problems and had to be returned (under warranty).

Ok....under warranty, can be fixed or replaced, but my question remains...

what gives? Can I not just buy a 2013 DRRI and pay $1,000 and expect it to not have any defects and sound great? I know for a fact that the sound would be good enough for me and better than my playing.....if it works.

I don't want any "motorboat" or clicking or nonworking tremelo or reverb when it first comes out of the box.

I simply want it to work as it's supposed to without having to bring a brand new amp in for repair under the warranty.

If one reads the reviews and MULTIPLE threads on this topic here, one might get the impression that there is a full-on 90% chance of getting a defective amp!!!! What gives, Fender?

It's like these $1,000 reissue tube amps have all sorts of issues just like the mustangs supposedly had the fizz problems.


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Post subject: Re: '68 Deluxe Reverb problems...
Posted: Tue Oct 15, 2013 8:40 am
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Amerigo wrote:
Her Wanna wrote:
Is it possible to buy a good tube amp today?


Victoria "Victoriette"?


Victoria offers some very nice clones -- ruggedly built, competently assembled, and utterly reliable. Just as the originals from which they were inspired.

The Allen Amplification products are quite similar.

Arjay

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