This is the latest version of the custom FRENZEL HB1 Hot Box Tube Preamp. This preamp provides so many tones and overdrive that it will drive you crazy trying to choose the one you want. Perhaps a more detailed description would help. I am sure all you guitar guys know about the vintage Matchless Hot Box,and what a great tube effects pedal it was, so I won't go into a history of it...but I will tell you a little about the original Hot Box circuitry. The original Hot Box used two 12AX7's. They were wired so that, in the clean mode, you had one stage of gain, with a Gain control. The clean stage had a bright cap and some other audio filtering that made the tones sparkle. For the boost stage you had three stages of gain, with circuitry very similar to the vintage Marshall preamps. The boost channel had Gain and Master level controls. The three stages of gain drove a cathode follower which fed a two band tone stack. All in all a really ace combination....but despite it's excellence, it had a few problems and we have endeavored to correct them by listening to suggestions made by our "rock on" guitar buds.
The first change was to replace two band tone stack in the Boost channel with a 3 band type tone stack similar to the one was used on the JTM 45.This stack allows you to create a much wider range of fantastic overdrive tones. We also changed the CLEAN/BOOST channel switching circuit to use a sealed ultra low noise relay to eliminate switching noises and loud pops. Another problem with the original Hot Box was that they all had a lot of 60 cycle hum. We have corrected this by using DC on the filaments. In the CLEAN amp section we installed a BRIGHT pull switch on the Clean Gain control. These two changes give you a much larger range of tones. Also, a second pushbutton was added to the footswitch to allow you to completely bypass the Hot Box. This gives the player three options.....Bypass, Clean, and Boost. Regarding the footswitch, we have added LED's so that you know which mode you are in.
Additional features include a standard IEC plug-in 3 prong ground power cord and all point-to-point handwiring. The controls are Input, Clean Gain with Bright Switch, Boost Gain with Boost Switch, Boost Bass, Boost Mid, Boost Treble, Boost Master, Power LED, and Power On/Off. The rear panel has a 1/4" footswitch jack, 1/4" Output jack, Output Level control, and power line fuse. The tube line up is 2 -12AX7's.
If you have never played through a Hot Box... you are in for a real treat. If you have, you are still in for a trip, because of the new features that have been added. It makes any tube amp sound better......and for you guys with solid state amps who are craving that vintage tube sound, you can insert it in front of your solid state amp and get that classic Hot Box preamp tube overdrive distortion tones.
The preamp is built into a 2U rack mount chassis. It is constructed with all top of the line parts....Neutrik heavy duty jacks, JJ 12AX7's, Micalex premium tube sockets, polypropylene caps, metal film resistors... etc. It comes with a two button Marshall style footswitch.
Input Jacks isolated from chassis to eliminate eddy currents and hum.
DC on filaments to eliminate 60 hz hum.
Star ground system to eliminate induced current chassis noise.
Hot Box Clean and Boost Channels or Bypass selected by dual botton footpedal switch.
Classic 3-BAND TONE STACK for extended flexibility in shaping your tone.
Bright Pull-Switch on Gain
MASTER level control on Booost channel so you can overdrive the preamp without overdriving the output tube.
Preamp tubes are JJ 12AX7's known for low noise and linearity. You may also use 12AT7's or 12AU7's for different tones and less preamp overdrive.
Classic Knobs and Toggle Power Switch
Standard IEC plug-in three prong grounded power cord.
Rock solid point-to-point hand wiring using only the best of parts...low noise tubular polypropylenes caps, metal film resistors, Micalex sockets, Neutrik jacks...etc.
Sweet vintage clean to classic overdrive tones with three different types of distortion depending on whether you are overdriving the preamp, output... or both!
Weight - 8 lbs.
Dimensions - 19"W x 12"D x 3.5"H
2U Rack Mount Chassis Cabinet
Tubes: 2 - 12AX7 preamp
BOOST GAIN WITH PULL BRIGHT
BOOST BASS WITH PULL DEEP
POWER CORD SOCKET
LINE OUT LEVEL CONTROL
Hi Jim, Your HB-1 preamp is awesome! It can be sweet and clean or warm with gobs of gain! Thanks so much Frenzel family. Doug F. ( New York)
Hi, I received the Hot Box HB1 preamp, but I'm not sure if I like it. Because I absolutely Love it . BTW I appreciate the status emails, its been very personal. Thank you, and Kudos. Rick C. (Kansas)
"I will never be able to play without this preamp in my life, its the best thing that had happened to me since I played guitar for the first time, nothing comes close to the quality of what you have built... it sounds like heaven. Nothing else to say." Thank you Jim, you are building a legacy. Cesar L. (Guatemala)
"the unit works beautifully and sounds terrific. I only started playing with the different settings - and then played with it splitting the signal between the Blues Junior amp with the HB1 and the piezo output to a Crate acoustic amp. Amazing to have the warm overtones accompanied by the clean acoustic sounds." Thank you very much! Scott B. (Maryland)
Hello Frenzel Amps - I love my HB-1 and have had a great experience as your customer. I purchased HB-1/RACKMOUNT serial 2315070 on 9/28/2015. I use the clean channel as an always-on preamp with my TC Electronics G-system (in the insert loop) and going into a Quilter Power Block head (set to line level input). It adds depth and sparkle and is the foundation of my sound. I use the G-System to switch the HB-1 to overdrive for leads and a creamy distortion. Great product and superb value! Mike F. (California)
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