Varistor for magnatone vibrato?

[sluckey]

I'm still trying to layout a board from the 410 schematic  I must have rearranged the caps and resistors 10x already just for v1 & v2

Only 10 times? That's about par for the course. 

I got 2 PMs from you yesterday.

[lego4040]

I shall keep at it, the main important one was that I was gonna go ahead and build this and was interested in a layout designed by you if you free.

[sluckey]

I'll get started on a layout but I've got a couple other projects I'm working on. It may be a week or so. Meanwhile, keep plugging away at it. May I suggest you start a separate thread?

There are some things I don't like about this amp, but I have to remind myself that this amp was close to the bottom of the Maggie line. It only cost $120 brand new.

[lego4040]

No rush Steve, I still got to finish the 5G9. I do like the troubadour a lot as well, which circuit do you prefer? I will start a dedicated thread to the Maggie build

[Willabe]

That's about half the price he was getting for those varistors a couple years ago. I think that means that a suitable, cheap alternative has been found.

I read through some of the link that K posted, mainly the last 3 pages, and listened to a couple of sound clips.

On 1 sound clip the guy has the alternative they came up with followed by a pair of NOS varistors. I think their both the single stage Maggi circuit?

I thought the alternative was not as thick and 'watery' sounding as the NOS clip. I wish he would have played the same part/chords back to back for both, with an A/B box. It's a little hard to really tell the way he did it.

They said that the Maggi circuit with varistors has a lot of trem mix with the vibrato portion and the fans of the Maggi sound like that. They consider it part of the uniqueness of the Maggi's sound. They said that the Vox/Gibson was more true vibrato without the trem added/over laid.

They also said some think that the new Maggi's are using varistors from Metrosil in England that still make silicon carbide varistors.

So I sent an email to them yesterday and was quoted a price of, $150 min. purchase order and for the 100-P/W/921, $27.25 each, $163.50 for 6. That does not include a vat tax and shipping. I just replied to them for what they would total.

I did not find in that thread that anyone over there tried the Metrosil varsitors.


                       Brad     

[lego4040]

When your building an amp cause it's your passion I could see paying that 27$ a piece for a one off amp of your own. As a business that might not make sense unless you have clients willing to pay for it + the markup

[Willabe]

Depends on how much you want that sound and how much $$ you have?   

I'm not sure at this point that I like the Maggi vibrato sound better (I do like it) that the Gibson/Vox vibrato or Sluckey's (Hammond) Warbler vibrato.

Those can be built for less $$ then a 1 stage Maggi, cost would double for the 2 stage Maggi. And the Warbler is a 3 stage.

Now on the other hand, we pay for tubes that wear out and I've not heard of varistors going out, sooooooooo.


                    Brad   

[Willabe]

Did you pay $50 for the pair or $50 each?


                  Brad     

[lego4040]

$53.50 for a pair. Shipping is the $3.50

[kagliostro]

If I can say ....

Build the amp you like, use the Ampgarage alternative to the Varistors (that are cheap)

if you like the sound of the amp and you didn't notice differences from Varistor use, all is done

if you prefer the original sound of the varistors, get a pair of it and install on the amp

Franco

[lego4040]

Here is a Maggie Vibrato I etched out and built last year. Pleasent sound and I used tag boards site for the build

[Willabe]

$53.50 for a pair. Shipping is the $3.50

Ok, thanks.

I just pulled the trigger and bought 2 pair.

I figure I can build it and try the NOS against the alternative and see what I think. Then if I hear no/very little difference then I can sell the NOS varistors or the whole amp.


                   Brad   

[lego4040]

Brilliant, I will follow that idea as well

[Willabe]

Remember you got me into this purchase and if it doesn't work out,   


              Brad     

[lego4040]

 

[Willabe]

I'm just joking around with you.   


                 Brad   

[lego4040]

I know that I've been trying to turn the Maggie 410 from a schematic into a layout which I've never done before. I'm getting there, it's like a jigsaw puzzle. I am using layouts from here as guide lines as to how and where things need to go

[Willabe]

It is like a jig saw puzzle, you'll figure it out.


                   Brad   

[kagliostro]

Here you can find some documentation and you can copy a layout

the layout is never been shown in a perfect view

but you can copy it among the pages and refine by yourself where needed

http://www.tdpri.com/forum/shock-brothers-diy-amps/511523-next-4-ish-builds-magnatone-210-410-discussion.html

K

p.s.: Here a good version of the schematic

http://www.magnatoneamps.com/schematics/magnatone_410rd.pdf

[Willabe]

Thank you K for all the links you've been posting on the vibrato.   

Go to post #70 for a sound clip.


              Brad   

[lego4040]

That is the schematic I have been using and that link you sent is great. He did a combo of layout/ PTP on his build I see. I'm using graph paper and using Dougs width dimension. If there is a cap can10/10/20 I will use that but I didn't even look for that yet, Dur. That would save me 2" at least on length of board

[sluckey]

https://www.tubesandmore.com/products/C-EC20-10X2-450

[kagliostro]

One other tread (at Ampgarage) about the previous 410 project, same author


http://ampgarage.com/forum/viewtopic.php?t=26485&sid=1f866c562d19de88def23c15%20b5a8c6dd


Franco

[lego4040]

Here they are

[sluckey]

I've added a layout for the Magnatone M-410 to my website. The layout has been verified to match the schematic, but I have not built this. It's on the drawing board.

    http://home.comcast.net/~seluckey/amps/index.htm

[lego4040]

    will print out and start the madness

[Willabe]

By the way, I've attached some pics of the originals, and a a word doc file with the specs for them. They are the two highlighted.

I can't get the dock open, anyone know how?

Link from reply #16;

http://el34world.com/Forum/index.php?action=dlattach;topic=14650.0;attach=33331


           Thanks,  Brad   

[sluckey]

Opens fine for me. I'm using Word 2010.

[jojokeo]

Does anyone plan on building a higher power 2x6V6 version maybe w/ 4 varistor circuit? It seems that the 4 varistor circuit would be a better plan/value since going to the trouble & cost of building something in the first place? I'd like to have something I can use for gig situations not just a bedroom amp. What Maggie model(s) would be suggested for what I'm looking for?
 
Maybe I'll consider just doing a one-off? If I did (going by memory here) didn't Maggie amps use a cathodyne pi with this circuit or does it matter and I can use a LTPI?

[kagliostro]

A GEM Super Deluxe Reverb 50R (old italian Brand) ? 



Franco

p.s.: @ Brad -- Our friend Darryl used rusian varistor on one of his amps - http://www.guitargear.net.au/discussion/index.php?topic=31524.0

[Willabe]

Opens fine for me. I'm using Word 2010.

I saved it then I had the option to open it with Word. It worked.


                     Thanks,    Brad   

[Willabe]

p.s.: @ Brad -- Our friend Darryl used rusian varistor on one of his amps - http://www.guitargear.net.au/discussion/index.php?topic=31524.0

Thanks K, I just read it. It seems the 56V SiC varistors gave a weak vibrato sound, but they did work.

He did mention maybe the circuit needed to be tweaked for the 56v Russian SiC varistors.


                     Brad     

[Willabe]

Does anyone plan on building a higher power 2x6V6 version maybe w/ 4 varistor circuit?

Yes, I might. I want to bread board it 1st.

I'm trying to find current production SiC or NOS Russian SiC varistors that will work. And I want to A/B the replacement they came up with at Amp Garage. K posted a link to the thread above, want the long and short of it? It works very well but it might not be as 'watery' as with NOS SiC varistors? (Start at page 9?)

What Maggie model(s) would be suggested for what I'm looking for?

There's a bunch of them. Some were 2x6V6's. I think that what guys liked the best about Maggie's was the vibrato and you can put that circuit in about anything you want. 

(going by memory here) didn't Maggie amps use a cathodyne pi with this circuit or does it matter and I can use a LTPI?

Yes and yes.

Edit; Should have wrote, yes, no and yes. Although there are a few Maggies the insert the varistor circuit between the PI driver and the splitter.


                 Brad   

[jojokeo]

I'm trying to find current production SiC or NOS Russian SiC varistors that will work. And I want to A/B the replacement they came up with at Amp Garage. K posted a link to the thread above, want the long and short of it? It works very well but it might not be as 'watery' as with NOS SiC varistors? (Start at page 9?)

I read that entire thread and listened to all of the sound samples. Even the best of the tried circuits were not as good sounding as the NOS varistors in my opinion. Some were weak sounding, some only modulated the upper frequencies, many had the diode switching/clicking going on, when caps were used it removed high end of the signal, etc...so nothing matched the good ol' Maggie sound & performance varistors. It was also mentioned that the inventor of the circuit spent time with the staff to show and teach them how even when using the original varistors it took many of them to get the right/correct match for the circuits to get them to operate correctly.
 
Reading the feedback of the guy that was selling the NOS parts was a lot of good remarks so they must work, unless the remarks were made before they were installed into the amps/circuits?! (doubt it but you never know?)

[sluckey]

Reading the feedback of the guy that was selling the NOS parts was a lot of good remarks so they must work, unless the remarks were made before they were installed into the amps/circuits?! (doubt it but you never know?)

He's a good guy. He also builds some nice amps.

[jojokeo]

He's a good guy. He also builds some nice amps.

Thanks Steve, that's good to know. What's your opinion on the best sounding Maggie Vibrato amp: 2 or 4 varistor version? Is there a big difference between the two? I've not played original Maggies personally.

[sluckey]

The M10A that I have is the only Magnatone I've ever heard. It has 4 varistors and sounds good to me.

[lego4040]

Right now it seems the NOS is Cheaper then what is being used in the new Magnatone Amps. There were three pair on eBay, I got one set, Willibe another so that leaves one set left on eBay so doing a dual pair might be hard.

[lego4040]

Right now it seems the NOS is Cheaper then what is being used in the new Magnatone Amps. There were three pair on eBay, I got one set, Willibe another so that leaves one set left on eBay so doing a dual pair might be hard.

[clyde]

Would these work?

[Willabe]

Maybe. They made them in MANY different values.

Can you see any #'s on them?


               Brad   

[clyde]

Not really and I'm sure some are thermistors.  If anyone would be willing to test them I could send some their way and when results are known I'd be happy to share if they're of any value, possibly for a PayPal gift for postage, etc. 

[jojokeo]

Even if you did have a couple of SiC varistors you'd likely not have the right ones. It'd be easier & much faster to check/test them all if you had a known amp with the circuit and simply alligator clipped them in and see what the results were immediately.

[clyde]

Unfortunately I am in the middle of renos as well as dealing with some heavy family issues and cannot get to this anytime soon J.  However, my offer stands if anyone wants to test them I'd be happy to send them and if they're suitable, then share with those that want.   

[mresistor]

what is "renos" ?

[jojokeo]

what is "renos" ?

renovations

[lego4040]

Willibe these are my readings

[sluckey]

Hey lego, will two of those varistor leads fit into the top of one of Doug's turrets?

[lego4040]

Good thing I stuffed everything in my duffle bag, 5g9 build as well. I will let you know by tonight or tomorrow the latest if that's ok. I think you should be able to, his turrets have nice inner diameter.  In transit at moment headed home

[Willabe]

No 2 won't fit in Doug's turret.

Lego check yours to make sure I have Doug's turrets in my hand. I might have some here from years ago from Mouser.


               Brad