Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: LooseChange on August 12, 2013, 07:47:26 pm

Title: Another Twin Reverb Preamp - Cool picture.
Post by: LooseChange on August 12, 2013, 07:47:26 pm: Just finished and shipped another "Jerry" preamp.
Just a cool picture from inside the chassis.
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: DummyLoad on August 12, 2013, 07:56:10 pm: very nice work LC.

--pete
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: Tone Junkie on August 12, 2013, 08:54:21 pm: Keep that amp Porn coming LC we love it.
Bill
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: Willabe on August 12, 2013, 09:23:27 pm: Dan, your work looks better and better if that's possible. I think your layouts, from experience, are very developed at this point too.

Very nice. It seems guys are really liking this Jerry pre?

Brad :icon_biggrin:
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: rzenc on August 13, 2013, 02:19:21 pm: Outstanding work LC!!

Are you using AC or DC heaters?

Best Regards

R.
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: TIMBO on August 13, 2013, 03:42:54 pm: SUPER :occasion14:
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: floyd on August 13, 2013, 05:41:05 pm: Another amp first.. an onboard interior cam to record NOTHING HAPPENING "SMILEY FACE SMILEY FACE "
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: LooseChange on August 14, 2013, 03:49:54 am: Amp cam!!!
The preamp is a rack unit and will be placed in a rack.
The heaters are lifted DC.

This is another Jerry Pre. I've built a bunch of these and shipped them all over the country and Canada.

Thanks for all the great comments! I share my stuff here because you guys always appreciate the "geek" work. I get the usuall "Uh Huh" from the wife and kids.
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: Tone Junkie on August 14, 2013, 04:44:13 am: Isn't it a drag when the people around you don't understand when you just finished a masterpiece LC.
Its like my Jam room the other day the wife says how many amplifiers do you need you have a whole wall now. My answer well honey its kind of like your shoe's, I don't have one of each kind yet.
Which she stormed off not understanding how my stupid amplifiers could be anything like her wonderful shoe's (LOL). The fact that you have garnered such attention for your Jerry pre's is a testament to itself you found a nitch and put out a good product, and people have responded well to it. Good work LC. we look forward to future amp porn offering's and appreciate your sharing with us .
Thanks Bill
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: LooseChange on August 14, 2013, 04:59:51 am: Ha!
Here is a front view from outside of the amp.
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: Ed_Chambley on August 14, 2013, 06:32:21 am: Dan, would you share the schematic and the layout for this. The layout is very nice IMO. I am getting ready to build a twin pre and really like this one. It is beautiful. Also if you have it, a list of materials. Mainly the transformer. It looks like it says toneclone.

You may have done this, but I cannot fine it in search.

Thanks!
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: LooseChange on August 14, 2013, 03:57:35 pm: The schematic is a Twin Reverb preamp AB763.
I hope you understand but the layout is mine and I will not share. Sorry!
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: Ed_Chambley on August 15, 2013, 06:20:08 am: Quote from: LooseChange on August 14, 2013, 03:57:35 pm
The schematic is a Twin Reverb preamp AB763.
I hope you understand but the layout is mine and I will not share. Sorry!
In that case it is the ugliest thing I ever have seen. :l2:
Sure I understand, but it doesn't hurt to ask. Not a problem at all.
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: archaos on August 15, 2013, 07:56:31 am: Awesome job LC ! Very neat & a real pleasure to see. That's not so common to see preamp tubes installed directly on the circuit board. You used radial electros so as to reduce the footprint ?
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: LooseChange on August 16, 2013, 05:13:21 am: Thanks!
First I needed a 2U Rack chassis to house the transformer. Then I wanted to make the entire circuit on one board to make it efficient for building a bunch of these. The under board wiring is a bit time consuming tho'. The entire process is a bit tricky too. I had to make a tool to install the reverb pan and even the chassis needs a process to assemble. I've have now built a bunch of these. They went across the U.S and in Canada too.
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: tubenit on August 20, 2013, 05:26:05 am: LC,

Great stuff as usual! I love your innovative approaches to ideas like this. Looks super!

Thanks for sharing the idea and photos.

With respect, Tubenit
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: Fresh_Start on August 22, 2013, 11:48:46 am: Fantastic work Dan!

I completely understand not sharing the layout but would you mind sharing a pic of the underside of a tube socket? I'm curious about the hardware and connections.

Chip
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: LooseChange on August 24, 2013, 06:57:47 am: Thanks again!
Here is a picture of how I do the underneath stuff.
Definitely adds to the build time. Plus you need to do everything in a mirror. :)
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: LooseChange on January 26, 2014, 05:49:26 am: More preamps in the Queue...
Two twin Reverb preamps and an Octal Preamp.
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: Platefire on January 26, 2014, 07:20:57 am: Great work and to find a nitch in the market that you can sell a great product is awesome. Just looking at your preamp, I do have a couple of questions:

1-People that are buying these, what kind of a power amp system are they matching these up with? I guess any amp that has a power amp in, you just plug it in---or maybe direct studio recording?

2-Reverb-I didn't notice a tank. How does this work?

Platefire

On an added note--I recently picked up a SS but vintage Shure mic pre. I tested it out by hooking it up directly to a clean amp but was surprised at the flexability in feel and response I got by dialing in a little extra gain. I plan to replace the rca high impedance inputs with 1/4 jacks and use it more in the future. I suppose your preamp could be used the same way with a lot more control.
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: LooseChange on January 26, 2014, 11:04:20 am: Power amps vary.. The Jerry guys like the McIntosh stuff. Everything from Jerry's favorite 300 watter down to those 50 watt solid state models.
Others are using Peavey tube power amps and there are some VHT's out there as well.
The tank is hanging inside the chassis.
Thanks!
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: LooseChange on January 27, 2014, 04:11:04 am: Plate, Here's another picture inside. See the tank hangin' up on the right. It's actually just the spring assembly.
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: shortfuse on January 27, 2014, 08:35:19 am: Dan beautiful work as usual any sound clips on these?
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: Platefire on January 27, 2014, 10:15:32 am: Yeah Thanks, I see it now but that generates another question and I understand if you would prefer not to answer--do you buy the springs/transformers in a tank and remove them or do you buy those parts from some source an assemble them in the amp. This may have been done before with reverb in amp chassis, but I just haven't seen it before. Think it's a good idea in limited space to get rid of the housing and go with the guts. Platefire
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: smackoj on January 27, 2014, 10:22:02 am: "jerry's fav the Mac 300" aaaa, do they sell those at swap meets and pawn shops bcuz I ain't never come across one?

:laugh:
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: sluckey on January 27, 2014, 10:43:07 am: Quote
This may have been done before with reverb in amp chassis, but I just haven't seen it before.
Doug did something similar with his rack mounted Revibe a while back...

http://www.el34world.com/projects/ReVibeRack1.htm (http://www.el34world.com/projects/ReVibeRack1.htm)
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: FranciscoPerez on January 27, 2014, 10:45:37 am: Wow!! Looks great!
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: LooseChange on January 27, 2014, 07:34:07 pm: I would love to get the reverb unit without the tank but haven't searched very hard. I remove them and install in the chassis.
I saw this in a TUT book.

I added a Reverb Dwell control to the back of one of my most recent builds. Definitely a plus.

Thanks!!
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: sluckey on January 27, 2014, 09:16:36 pm: Dan, did you just bolt it directly to the chassis or are you using some shock mount or dampening device?
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: HotBluePlates on January 27, 2014, 11:26:00 pm: Quote from: sluckey on January 27, 2014, 09:16:36 pm
Dan, did you just bolt it directly to the chassis or are you using some shock mount or dampening device?

If you look very closely, you can just make out the springs that run from the corners of the assembly to chassis mounts.1 spring in each corner of the reverb assembly.
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: kagliostro on February 02, 2014, 07:46:48 am: Very nice execution Dan :thumbsup:

I've a question for you

which kind of output do you use in your rack preamps, a CF

or the circuit is completely the same of the preamp to which you "inspired" ?

Thanks

Franco
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: LooseChange on February 03, 2014, 04:54:01 am: Right off the plate just like the Twin. Added and output level.
Title: Re: Another Twin Reverb Preamp - Cool picture.
Post by: kagliostro on February 03, 2014, 05:20:22 am: Thanks

Franco