Want to add preamp out to Monarch circuit

[pullshocks]

I have updated my breadboard build of the Benson Monarch with changes to the power supply from recent posts on Ampgarage--basically powering the reverb circuit with a 5th power supply node.  Big improvement, the "bleedthrough" issue is pretty much gone.

I would like to add a preamp out to see what it sounds like with my Solow Watt and 5watt SE amps.  I don't see a need for a power amp in, just the preamp out.


Attached are my as-built schematic and schematic of the proposed preamp out.  Would appreciate any comments or suggestions for a better way to do it.


Thanks

[sluckey]

Your preamp out jack looks fine to me.

[pullshocks]

thank you Sluckey

[bazookajoe]

Can't get in the ampgarage forum (no emails to "forgot my password" or new registration) to discuss there
I can not believe that this is the famous mysterious exclusive expensive Benson Monarch, that looks just like any old 1940s paraphase inverter amp like a GA40, GA 20, Supro Supreme or similar.Been wanting to build one for a long time, must really do that one.

[roarshock]

Pullshocks,
Thank you for correcting the switch on that schematic! I can't believe that no one else has changed it since that was posted a few years back. I came to your conclusion but didn't trust myself at first because so many eyes had already seen it. I hope you enjoy your build!

[pullshocks]

I can understand your frustration with account registration at Ampgarage.  I don't know the whole story, not sure what to tell you. 


As far as the Monarch, yes it is a cathode bias, push/pull 6V6 power amp and paraphase phase inverter.


I participated in the first couple years of the long Monarch thread on AG.  Some issues, like the voice switch were wrong in the originally postesd schematic but got worked out (I'm not the one who solved the problem).   I got a version of the circuit working on my breadboard back in 2021.  Great sounds, but afflicted with the dreaded “bleed through” weirdness.  As stated above, the 5 node power suppy seems to largely solve the bleed through issue and AFAIK Benson now uses a 5 node power supply.  I wonder what the early  real Benson Monarchs with the 3 and 4 node power supplies were like.


Some people reported loving their builds from the available schematic, and did not mention the bleed through and hum issues that afflicted others of us.  Maybe they didn't have the problems, or corrected them and did not report how they did so.  Or they felt the good qualities of the amp outweighed the issues, and they just decided to live with it


“Hoodnight” tried to pull the available info into a schematic and layout he posted here:  Benson Monarch Reverb - The Amp Garage .  It includes a 5 node supply, and from my experience it may well turn out to be a “definitive” schematic.  But I haven't built it and I don't know for sure.  There have not been any updates or build reports on that thread since he posted it over a year ago.


In my breadboard build, I love the full, rich tone at low volumes.  The overdrive sounds are great too, but I just play at home and the sound pressure levels are too high for my use, at least not without an attenuator.   

I think the American/British switch works well, and gives 2 good sounding voices.  Last time I looked at the Benson web site, they had updated the Monarch with a bass control instead of the switch


So the 6V6 push/pull Monarch is overkill for my needs, and I will not be doing a permanent build.  After listening to demos of the Monarch and the Nathan Junior, I decided not to pursue a low watt version.  After all that work, I hate to walk away from it, but I need to try something else on the breadboard.  So I'm about to say goodbye to the Monarch.

[bazookajoe]

Thanks for your reply. Unfortunately without being logged in i can not see any pictures or other attachments on ampgarage forum. Looks like its not possible for me to get a new password or register new.
(and just spent one and a half hours trying to read the LTspice or DILC files - not sucess, tried several versions), would have been more long term usable if he had jpegs on github.

I have planned to build a simple GA20, Supro Supreme "ish" amp, somewhere found a "GA20 lite" schematic and this looks very similar to the monarch, other than the octal tubes. Will probably build without reverb to keep it even more simple.
And yes i also play in the living room with neighbours behind a thin wall and my successful build (in ratsnest prototype status for years) is a low voltage champ, 6SJ7 into a 6G6, probably half a 12AT7 and a champ tone control in front. And i even have a voltage regulator in this.
If it was not so simple i would be proud, boutique makers would sell this for 2 K. Wenn i listen to that Benson Vinny clip i am really proud of my build, that sounds terrible.
I will probably build that although it is too loud, want to build a champ and a deluxe style amp after my low voltage amp, just to prove i can do it. And already have all the parts. (For years)
For layout i am not very skilled with that but will follow the Fender paraphase layouts and there is an excellent build documentation with schematics and a layout of a GA40 around, i can adapt that.
What just really astonished me that this mysterious exclusive boutique amp is such a common 1940s schematic. All that talk about that he dissected numerous vintage amps over years and let the what he liked best flow into the Monarch circuit - thats completely exaggerated or not ? You really have to have a good story to sell products, but i am a little disappointed about this.
I bet my amp will sound just as good. Actually i had a Tone King Falcon sitting besides my build and my old champ and sent it back because it was not better, it was nuances different but not better.

[passaloutre]

Just because it's boutique doesn't mean it needs to be a groundbreaking circuit. By all accounts the Benson amps are well made, and I don't see a lot of paraphase inverters in the boutique world, so at least they're offering something somewhat unique in the current market.

If it sounds good, it is good.

[bazookajoe]

Sure. To sell sth. thats simpler like a boring old 5E3 clone for 3 K or more and have a waiting list (that is closed) is 95 % Marketing, not the product.Like some pedals that are a one transistor boost with parts value of 30 bucks and sold for 300 with a good story.Well i am glad that i did not fall for it and order one. And my very poor DIY skills are good enough to build sth. i like better than anything on the market.

[passaloutre]

Sure. To sell sth. thats simpler like a boring old 5E3 clone for 3 K or more and have a waiting list (that is closed) is 95 % Marketing, not the product.Like some pedals that are a one transistor boost with parts value of 30 bucks and sold for 300 with a good story.Well i am glad that i did not fall for it and order one. And my very poor DIY skills are good enough to build sth. i like better than anything on the market.

I'm not sure I've ever seen marketing from Benson, at least not for their  amps. I would guess that price is 95% overhead. Operating a "handcrafted" manufacturing business in a large American city is not cheap. It's easy for us on a DIY forum to say "that amp only has $500 worth of parts, what a ripoff!" but we don't have lights to keep on or employees to pay. And for what it's worth, they don't seem to be skimping on transormers, components, hardware, cabinet, or speaker quality. I'd guess their materials for something like this are closer to $1k (ignoring any volume discounts they might get).

Anyways I think it's a cool amp, I'd rather have it than the millionth tweaked Fender circuit out there.