Insides of Lazarus H-1A amp...

For anyone who is interested..
Looking at your pic, I am strongly inclined to say that you have the H-1 amplifier, and not the H-1A. Here's a pic of the H-1A ..

The H-1A has a more sophisticated main power supply, dual power rectification, increased voltage stabilization, and reduced loading on the output of the tube stages. Also, there are high voltage (160uf, 450v) capacitors directly at the plate resistor of the tubes for better separation, image stability and dynamics.

If you think the H-1 amp is good .. feast on the H-1A, or better yet, a Lazarus "Class A" high-current amp with 4 tubes. They will blow away the H-1 ..
hey...I did see this pic,,,,i noticed the differences, but didnt know enough to make heads or tails....

Which Lazarus has Class A with 4 tubes?

The "Class A". This model is Lazarus's best stereo amplifier. These amps have TRUE class A designs, unlike all other models which only have pure class A designs.

The "Mark II" also has 4 tubes.. with a pure class A design and a high power output.
Well, 'pure' class A or 'TRUE' class A, my H1 sounds quite good. I just wish I could find a schematic diagram for it. Any of you owners have one or know where I can get one? I'm willing to pay something.

Jeff, you might be able to obtain a schematic here..

"Manuals and schematics available for $50.00 USD plus shipping, all models."
Jeff, I doubt you will be able to find a schematic.

I bought my Lazarus directly from Andy (?), sorry I can't remember his last name, and I'm not sure that Andy is his first name either, but he was the designer/owner of Lazarus. He wasn't very organized or interested in helping me when I had a problem shortly after purchasing my amp. I would be very surprised if he ever had a schematic in the marketplace.

Last I heard he was designing for Muse.
Adonati, thx much. I've e-mailed them.

Fiddler, Lazarus's owner/designer is named Greg something. As a dealer in the '80s I did business with him.

Muse, huh?

About a year ago, I e-mailed Muse looking for Greg Miller. He doesn't work there. I'm thinking that perhaps he's still in North Hollywood, CA ?
Yep, thanks for refreshing my memory, Greg Miller. (Andy was close, hehe!) I went to his house in Van Nuys when I bought the amp. He seemed burned-out on the business, but that was because his business was floundering. I think he built really good equipment, he just had a hard time with capital.
I wonder if a good tech can take the H-1 to H-1A level? risky without schematics?

ALSO: has anyone tried the H-1, H-1A in mono?? most people I talk to seem to prefer stereo.
"I wonder if a good tech can take the H-1 to H-1A level? risky without schematics?"

Uuh...what would the tech DO? Without a H-1A schematic diagram and an H-1 amp, he/she wouldn't know what the differences (= upgrades) are.

Jsujo, yes.. risky to upgrade to the H-1A without schematics. But a good tech can always change the factory pc to something exotic and have the circuit board resoldered with lead-free, 4% silver solder. These tweaks will help. But if you're set on an H-1A, I have a lonely unit not in use.

I have two of the "Class A" models in mono right now, using the XLRs... sounds pretty darn good. :-)

If anyone is interested, I have lots of Lazarus literature & reviews. Jsujo, one review compares the H-1A stereo amp versus H-1A monoblocks. The monoblocks had more separation between instruments and better high frequency extension.
I have an H-1A and would be interested in any specifications (damping, slew rate, etc.) or literature available.

I am considering using it as the bass amp in my biamp system.
Jsujo, there are lots of improvements a knowledgeable technician can make to an H-1. It's full of capacitors and resistors, large and small, that can be upgraded. I've started upgrading caps on mine, replacing the lo-voltage PS bypasses on the bottom of the board. But I still want a schematic diagram of the circuitry before I do much more.
man, If i didnt just buy a VPI Scout TT with the Dynavector 20X cart, I would get your amp...

I will be interested in it, a little bit down the road,,,

Any chance I can send u some $$ for copies of the lit?


I've scanned a bunch of Lazarus literature at Kinkos today.
Let me know what you need ..

H-1A Brochure/Pamphlet (2 pages)
The H-1A User's Manual (7 pages)
Lazarus Pricing/Upgrading info (3 pages)
The Amplifier Story (2 pages)

I have a few more articles somewhere. I'll look for them.
If you have questions, e-mail me at


resurrecting an old thread!!!

Amazingly enough, my cousing who lives in California work with Greg Miller from Lazarus and ia rebuilding me a pair of monoblocks!

jsujo, adonti, etc

since you  are the most recent to comment to this thread....... I own 2 H-1a's and hope to get hold of any documentation, schematics, etc. in order to operate and upgrade these amps.  Any contact or info sincerely appreciated!