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Sweet Little AC15/30

"VOX Chime With Hot Box Overdrive"



  • Model No. HBX-AC15 - 15watt

  • Model HBX-AC30 - 30 watt (upgrade)

  • Push-Pull EL84 Guitar & Bass Amp

  • 4-8-16 Ohm Speaker Switch

  • Multi Power Level  1/4 - 1/2 - Full

  • Dual Channel VOX & HOT BOX Preamps

  • Separate Gains With Bright Switches

  • Deep Bass Switch

  • 3 Band Tone Stack

  • Cut Control With Edge Boost

  • Post OT Line Out With Level

  • Solid-State Rectifier

  • Tubes: 3 -12AX7, 2-EL84

  • Custom Upgrade Options

MSRP: $1255.00



Guitarist Description:  Bell-like tones …i have to say I really like the bright and deep push-pulls you installed...They seem to ’make the difference’ on my Rickenbacker 12-string tones - getting that chime and jangle in spades!  I’ve got the Boost channel set up to play live shows - and I’m getting what I need in that channel for Rickenbackers AND Les Pauls - really versatile!  And using the guitars’ knobs couldn’t be easier with this amp! Amazingly versatile for what I need to do live!  Chime, jangle, open, very musical…made for my Rics!!!!  And my Les Pauls are smiling too!!  John Z. (Ohio)

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The FRENZEL HBX-AC15/30 "Sweet Little AC15/30  is the latest version of our HBX-AC15. It has new features that many of our customers have requested. Like the HBX-AC15, it was "INSPIRED" by the classic  Matchless Hot Box and VOX AC15/30 amps....but the amp is not a clone and it has  more features than the original amps that make it really unique. The amp has two channels...Clean and Boost...that can be selected by an AB/Y footswitch. 

Channel 1 is the Clean channel with the classic VOX voice with a Gain control only like the original Normal channel on the VOX-AC30. You use your guitar controls to set your tone. It will faithfully reproduce what you put into it with minimal overdrive.  

Channel 2 is the Boost channel and has the Hot Box voice. It has three stages of preamp gain that will give you soaring dynamic leads with great clean and overdrive tones. The tone is further shaped by a classic three band tone stack and Master Level control.  

Both channels will give you that classic EL84 chime and they share a Cut control to fine tune the high treble tones. We  also added a NNFB Boost pull switch to the Cut control to defeat the negative feedback loop which gives a boost in volume and a more dynamic pick attack with soaring uncompressed tones.   All these added features produce an amp that will give you high intensity clean and smooth overdrive saturation tones. The FRENZEL HBX - AC15/30 also comes with all of the other standard features FRENZEL amps are famous for as described in the features list below. 

Standard Features:

  • Clean Channel  Input  and Boost Channel  Input with separate preamps and Gain controls for the unique smooth VOX warm tones or the Hot Box dynamic  high mid-tones....or you can use an AB-Y switch and create your own distinct tones.

  • Bright pull-switch on Gain controls.

  • Deep pull-switch on Bass control.

  • Classic 3-BAND TONE STACK for extended flexibility in shaping your tone.

  • Master level control so you can crank the GAIN's up and overdrive the preamp without overdriving the output tubes.

  • CUT control to attenuate the high frequency tones combined with an NNFB Edge Boost pull switch to remove the negative feedback and give you soaring dynamic response with practically no compression.

  • Line Out - post output transformer LINE OUT with LINE OUT LEVEL control for recording or driving a power amp, Auto switched internal load to simulate speaker if speaker is  not plugged in. Inject great tone directly into the PA system with the Speaker Simulated Direct Interface.

  • Class AB  Push-Pull EL84's for the purest reproduction of sound possible.

  • Ultra fast heavy duty high voltage solid-state rectifiers provide sharp pick attack and dynamic bass.

  • Power Output -  HBX-AC515 15 watts - HBX-AC530 30 watts (Upgrade)

  • Three Power Level Selector Switch - Provides three power levels. 1/4 -1/2  FULL.

  • Custom heavy duty output transformer for extended low frequency performance with 4 - 8 - 16 ohm outputs selectable by a rotary switch.

  • Standby Switch - Protects tubes from cathode stripping during warm-up. 

  • Tube Complement: comes standard with 3 - 12AX7,  2 - EL84's...but you can substitute 12AT7's or 12AU7's in the preamp and driver for different tones and overdrive sounds.

  • Open Chassis -  classic tube amp look to show off the tubes and great option for  DIY cabinet builders.


Electrical Specifications: 

  • Input Power  120 VAC 50-60Hz - 155 Watts Standard IEC plug-in three prong grounded power cord. (230 - 240VAC available. See Upgrade Options) 

  • Output Tubes - Class AB Push-Pull EL84s - Fixed Bias

  • Output Power   HBX-AC515 15 watts - HBX-AC530 30 watts (Upgrade)

  • Output Power Selector Switch - provides three power levels. 1/4 - 1/2 - FULL power.

  • Speaker Output Impedance - selectable by switch 4-8-16 ohms.

  • Line Out Impedance - 10K ohms

  • Instrument Input Impedance - 1 Megohm

Physical Data: 

  • Retro Vintage Cage Mini Head  - heavy duty lightweight steel mesh cage provides protection and excellent ventilation for tubes. Comes with easy carry Fender style strap handle. Overall Dimensions - 12" Wide x 10" Deep x 10" High  - 15 lbs.

  • Chassis - Heavy gauge aluminum with welded corners.

  • Rock solid point-to-point hand wiring with military style tie-wrapped wiring harnesses for long life and reliability.

  • DC on filaments to eliminate 60 hz hum.

  • Star ground system to eliminate induced current chassis noise.

  • Input and Output Jacks isolated from chassis for low noise, eddy currents, and hum.

  • Components - Only the highest quality parts are used including heavy duty transformers, low noise tubular polypropylenes capacitors, metal film resistors, Micalex sockets, Neutrik jacks. All parts are rated for commercial high use conditions. Wherever possible we use parts made in the USA.

  • Front Panel Controls - Clean Input Jack, Boost Input Jack, Clean Gain, Boost Gain, Bass, Middle, Treble, Cut/Edge Boost Switch, Pilot Lamp, On-Standby-Off Power Switch

  • Rear Panel Controls -  Power Cord Connector, Fuse, Line Out Level, Line Out Jack, Speaker Output Jack, Output Power Level Switch, Speaker 4-8-16 Impedance Selector Switch,. 

Upgrade Options:

These options allow you to  customize your amp to meet your special individual requirements.

30 WATT HBX-AC530  - uses a quad of EL84's like the classic AC30 for 30 watts of max power...three power levels 5 - 15 - 30 watts. Add $100.00

EFFECTS LOOP -  pure tube buffered serial effects loop designed to perfectly match the low impedance solid-state pedal levels with high impedance tube levels..  Add $75.00.

EF86  PREAMP TUBE - Replaces 12AX7 triode  in the CLEAN preamp with an EF86 pentode  for the classic VOX tones. Add $50.00

"SURFER"VINTAGE TUBE TREMOLO   - pure tube tremolo for those vintage vibe tones. Great for surf music! Comes with Depth and Speed controls on front panel and footswitch pedal. Add $95.00 

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DUAL RECTIFIER POWER SUPPLY - Power supply has a 5AR4 tube rectifier mode for that "saggy" smooth compression on peaks and a solid-state bridge rectifier mode for sharp pick attack and dynamic bass. Switch on rear panel selects mode of operation. Add $105.00


 Review and Sound Clips By Featured Artist  - Mike Ault

Cabinet with standard Celestion vintage 30's and a PRS Singlecut Hollowbody for all the guitar parts…I just added a little reverb to the guitars in places, not much. It's a nice sounding amp and i'm glad to have it. thanks, Mike

HBX-AC15 - Mike Ault
00:00 / 00:00

 Review and Sound Clip By Featured Artist  - Christer Fredriksen

 Hi Jim, I just wanted to let you know that I’ve made a clip using the HBX-AC15. It’s an arrangement of a jazz standard, Blue in Green, Miles Davis, best regards, Christer Fredriksen  Norway)

 Review and Videos By Featured Artist -  Jimi Jaymes


 Review and Videos By Featured Artist  Jimi Jaymes 

Review by Featured Artist Paul Stanfield (United Kingdom)

Hi Jim, As promised, please find below my thoughts on the two amps I own (FM-5E3DP & HBX-AC15).  Feel free to use them on your website. Best wishes from the UK! Paul Stansfield

INTRO - I won’t go into details of the features or construction as this information is available on Frenzel’s website - but rest assured, build and component quality is top notch.

FM-5E3DP   -  Plugging into the ‘F’ channel, you’re greeted immediately with a thick tone, full bass and grainy texture.  It’s a very ‘old fashioned’ tone and suits low output single coils. LIke a tweed Fender, you lose definition with more volume and the bass starts to get loose.  This cleans up quite nicely with the volume on the guitar and varying pick dynamics also achieves the same thing. Sticking a drive pedal that limits bass (such as a Tube Screamer) also works well, although gainier pedals on an already overdriving tone loses focus.

Into the ‘M’ channel things are much more tight and defined.  Keeping the master volume low and the preamp high, you’re greeted by a very decent yet low volume crunch sound.  In fact, regardless of the channel, it’s really good to explore the preamp vs power amp valve drive by playing with the input gain and the master volume.  It’s not classic Marshall (the output tubes in my amp are 6L6s) but it’s still a British sound. Bypassing the negative feedback circuit here is fantastic, it’s Vox-esque with some settings, especially if you roll off a bit of bass.

Pushing the gain levels, things stay much more together than the ‘F’ channel - gain levels are vintage Marshall rather than more modern amps - but putting a decent gain pedal in front gets you in that territory.  This channel really plays nicely with transparent overdrive pedals which allow the character of the amp to be maintained, but using a pedal like a Marshall Guvnor - Gary Moore’s blusier lead tones are created with ease.

The ‘M’ channel is my favourite of the two, but then I’m not really a lover of the tweed Fender sound.  Mixing both channels is fun too, I tend to dial in the ‘M’ channel the way I like it, then add a touch of ‘F’ channel to bring in some bass.  If you scoop the mids and lower the bass a touch while still using the mix of both channels and using the ‘F’ gain control to add bass back in, there are almost Blackface Fender tones if you keep it clean.


HBX-AC15  - The clean channel stays clean up to half way, then it transitions into a gorgeous Vox-like grit and chime.  This actually isn’t much like the ‘normal’ channel of an AC30 (I have two 60’s Top Boosts for reference, a 64 and a 65) it actually sounds more like the top boost channel but with less gain.  Obviously, considering my amp choice - I love the Vox circuit, I think it really allows the tone of the guitar to be reflected without the amp turning it into something else. The transition from clean to drive is a thing of beauty, and Vox-style amps do this better than any other amp in my opinion.  The Frenzel is no different - all my guitars ring and chime through this channel and as the gain control moves later in its travel, things thicken up slightly and overdrive is clear and dynamic.

The boost channel is clean  at lower gain settings, but it quickly moves into a focused and refined drive sound.  The glorious sound of a real AC30 at full tilt is a wonderous thing, but the Frenzel sounds like it’s working less hard to produce the goods.  It’s still Vox-eque, but there’s more gain and it stays together while still retaining the character of the guitar. Unlike a Top Boost Vox, the Frenzel is far less picky about gain pedals.  Transparent boost pedals work very well and even bright distortion pedals (which would be painful on an AC30) work nicely.

As with all things Vox, the Cut control is your friend - in my opinion, this control should be on every amp made - it’s perfect for globally controlling the brightness of an amp.  Adjusting the treble control of an amp always changes the gain and the texture of the tone - but you can set that and control the overall brightness with ease with the Cut control.

SUMMARY   All in all, I’m truly delighted with my Frenzel amps - both give me familiar sounding classic tones at sensible volume levels (albeit still loud if you want it to be) but with modern construction and quality.  They might not completely replicate the amps they’re inspired by, but that is a good thing. They have their own character but it’s clear which amps were the inspiration. They’re versatile but still simple and they record very nicely indeed.  The handy feature of a load resistor when there’s no speaker connected is useful, it’s easy then to record the amp through some speaker responses.

I really like the Deluxe Plus for its versatility, as it covers an awful lot of ground considering it’s simple circuit design but the Sweet Little AC15 is an absolute gem of an amp.  Less versatile perhaps than the Deluxe Plus but it nails the Vox character, and then there’s that boost channel which takes it beyond what an AC30 would do. This has been my favourite amp purchase for years.

I don’t know how Frenzel make money on these things, they are an utter bargain compared to other USA boutique amp manufacturers.  Thoroughly recommended.

Customer Reviews 

HBX-AC30 - Ok you did it again. My 3rd Frenzel- this time the Sweet Little 15/30 In a word "Stunning" The incredible clean clarity, overhead and flexibility has me stammering. I have been hunting for a few years for a mate to my vintage ES-335 and bought this one guessing/hoping it would be a match the way my other two FM-5E3 SD "Super Deluxe" amps match up to my Telecasters and I couldn't have been more right. Punchy, in your face presence, bell tone sustain,  same killer tube magic but a new voice in the stable. The 335 is out of retirement! Keep up the good work and thank you again. Leon T. (Oregon)   

HBX-AC30 - Hi Jim & Team Frenzel - I HAVE TO SAY:  WATCH OUT VOX AC15 AND AC30 HAND-WIRED, THERE’S A NEW KID ON THE BLOCK NOW !!!   So a big thank you for this marvelous HBX-AC30 amp - like “Wwwoowwww” !!!!  A TONE MONSTER!  Genius to use that Hot Box in an amp - What a sound! and such a value!!!   Bell-like tones …i have to say I really like the bright and deep push-pulls you installed (a big thank you - wasn’t expecting them on this build!) - They seem to ’make the difference’ on my Rickenbacker 12-string tones - getting that chime and jangle in spades!  I’ve got the Boost channel set up to play live shows - and I’m getting what I need in that channel for Rickenbackers AND Les Pauls - really versatile!  And using the guitars’ knobs couldn’t be easier with this amp!  The NNFB push-pull is a game-changer for sure, love that wide-open sound, great to have the option - same with the SS/rectifier tube option…All of these switches/controls really allow for many, many tones in this amp, just gorgeous! It is everything I thought it would be and more!! My Rickenbacker 12s have been looking for these tones - and now they’re here!  Amazingly versatile for what I need to do live!  Chime, jangle, open, very musical…made for my Rics!!!!  And my Les Pauls are smiling too!!  First class all the way!  You guys are hitting ‘em outta the park!! Thanks all again for a  great amp - John Z. (Ohio)


Hi Jim, I just got back home from university yesterday and had my first chance to play the amp you built for me during the summer. It really does sound great, I couldn't be more pleased with the amp. I'm sure as I play it more I will fall even more in love with the sounds it is producing! Many thanks for your first class product and excellent customer service, I look forward to many happy years with this amp.God bless, Andrew H. (Scotland)

Hi Jim, My Sweet 15 arrived today, safe and sound. I got it up and running and have played it for 45 minutes or so. My initial impression is wow, what an incredible range of tones this thing has. I haven't attached my pedal board to it yet. I was just playing it straight and dry with a strat and les paul.  Lots of exploring to be done here, but I can tell already that it has incredible clarity of tone. This amp is really going to cut through the band mix. -- (9months later) I have really been enjoying my HBXAC15 over the past nine months. Thanks, William E. (Canada) 

Hi Jim, I am from far east, Macau. I am a happy owner of  FRENZEL "Sweet Little 15" for more than 5 years & I really like the way, a guitar technician came to fix my guitars yesterday, he said my HBX-AC15 sounds very nice & he wants to get one too. Matias L. (Macau)

Hi there, Just received my order for an HBX-AC15. I just wanted to say how impressed I am! The build quality is incredible and the tone is off the charts! Just had a moment to plug in my Telecaster and WOW!!! Blew me away! Thank you so much for the dedication to supreme quality! Money well spent!!! Kind regards,  Gord H. (Canada)

Hi Jim, Finally the amp has come! Hallelujah! I have listened it and I like very much. It is a great amp! Best regards from Adrian N. (Spain)

Frenzel Team - Thanks so much for the Sweet Little 15, the best tone I have heard. I have owed many, many amps. Jonathan C. (California)   

Howdy. the HBX-AC15 was delivered today. Yes, you guys did great. Thank you. I had to wait a little while to get it home, and it will take a little while longer still to try a couple of different cabinets and with various guitars. My first reactions are only positive. It's terrific, and I suspect I will continue to find great things about it. I really like the implementation of the controls and the way gain structure is set- not too much, not too little. The push-pull pots are a great and highly usable idea. Love it. Great work!  Thomas C. (California) 

Hi Jim, I can not say enough about the quality and sound of the Sweet Little 15 and the Retro deluxe that you recently made for me. Every time I plug these in and get such inspirational tones with ease, and the value provided, WOW, Thanks, Mike H. (Victoria, BC Canada)

HBX-AC15  - Hello, I just received my HBX-AC15 amp yesterday and I'm very happy with it! Brian P. (New York)

Just blown away! Proud owner of a AC15 HBX ! Tone,tone,tone!!! Many thanks to Jim and the whole family! I waited on purpose to see if this amp was gonna make it thru the "Honeymoon phase" before posting a comment.Safe to say its a keeper! The cleans are perfect, the dirt channel is old school and there seems to be quite a bit of tweaking for various shades in between. To be honest, I haven't felt this good about turning on a amp and plugging in my guitars in a long time. Keep doing the fantastic work you good people do! Dan F.(New York)

Hi Jim, I am getting up to speed with this amazing "little" amp of yours. First let me say that a friend of mine that has quite a bit of amp experience was amazed by the soldering and layout of the AC-15. Very clean and impeccable were the words he used. I saw it for myself when we took the back off. As to the tone, my friend, a jazz guitarist, spent almost an hour with me exploring the tones that this amp can produce. I bought the amp thinking AC-15/30  jingle jangle Beatle's type tones with single coils, but this amp can go well beyond that. With 5751's in the gain and driver locations, this amp can produce warm almost acoustic type tones with channel 1 and a 1985 standard Gibson 335 guitar. With channel 2 and low gain and master levels there was definitely Larry Carlton type tone happening. The compression of the sound/tone was well separated and quite pleasing.  Richard S. (Pennsylvania)

Hello all at the Frenzel Magic Kingdom, I have been plugged in to my HBX sweet 15 since I received it last week and it has exceeded all my expectations! What great tone at any volume on the dials. very warm responsive goodness with plenty of fang when you want it. I'm shedding pedals because of this beauty and now must consider also having a super delux plus. I was just imagining those two running together and damn near passed out. Thanks again - swooning in tone, Philb of Sparrowbox   

Hey Mr.Frenzel! I've really been enjoying my 2xAC-15s since their arrivial! I've been doing some "stereo solo" guitar recording.Miked "Raezer's Edge"speaker cabs and direct out each running into a seperate Collins 212-pre.The tracking signal routes into a old four chanel"Collins 12-Z"broadcast mixer modified into a four channel stereo recording mixer which busses to a Ampex 351-2-track stereo. Pretty simple but it's working fine.Your amps are great and very tonally modular.They track great and record with real nice clarity and defination.So thanks a lot for a great product. I truly believe your products and services reside at the level of best quality and value to be found within the audio-electronic tonal production industry.This is my opinion, but it comes with many years experience. Respectfully,Frank P. (N-Cincinnati)  

Hi Jim,  last year you built a Sweet Little 15 amp for me.  I love it.  It sounds great, and is quite versatile.  I'm pairing it with an ear candy sovereign cab loaded with a tone tubby alnico 12".  Ps...just got out of rehearsal with my arena-hair metal cover band. The amp was sounding phenominal. Had the presence knob pulled out for NNFB, which allows the amp, in my opinion to get closer to a Marshall SS rect sound. The Sweet Little 15, thru one 12" tubby sounded like a full stack. No problems hanging with a SVT...and its tone was full and blooming. It never ceases to amaze me.  Many thanks, Tony D. (New York) 

Jim, Every time I plug into the HBXAC-15 I am amazed at the tone.  It has a chime to it all its own.  The Boost channel has that classic Vox sound, but it is so much better.  It is hard to describe.  You guys pegged the sound on this.  Do not change a thing. Mark H. (Texas)    

Hello Jim and Team - Got it. And got about 2 hours to myself this weekend to work out on the new Hotbox AC15 - LOVE IT - and I haven't even scratched the surface; all I did was plug in a guitar and play this amp through my Bogner Cube for about 2 hours; no effects, no nothing.... This amp sounds so damn good, I'm not sure that I need anything else. Thanks!! I'll be sending you a more thorough report later. Suffice it to say that I CAN'T WAIT to take it out on a gig...Best regards, Kent A. (Virginia) 

Jim, Wow! No wonder you are swamped.  Jim. I own some of the best amps in the world, and have been playing for 44 years.  I just got thru running your amp thru its spectrum of tones.  It was worth the wait!  I discovered a few years ago that it doesn't matter whose name is on the instrument, but rather what kind of person built it, and how much of themselves they were willing to put into it.  Obviously you love what you are doing, and you have put your heart and soul into the design of this amp.  I hope you dont get too busy cause I'm already looking forward to trying some of your other amps.  It's hard to put a price tag on an instrument with a soul, but you have the best bang for buck out there in my opinion.  Carry on brother, David R. (New Mexico)   

Thank you Jim for building a wonderful sounding amplIfier, you are a sound-craftsman and I am truly enjoying playing the heck out of it! Tony P. (California) 

I really have not heard an amp with as much chime and be as thick as it is. An absolute alchemy of parts and build. I've got 2 RCA 12Ax7s, 1 Sylvania 12AX7 and Mullard EL84s thru a Red Fang and a ToneTubby Paper cone that was reconed by Weber in a 2X12 pine cab. The wiring is absolute art. Beautiful clean construction. Just beautiful. Thanks Jim for making this amp with my transformer and making it so nice. I am most grateful Rob F. (North Carolina)

Hi Jim,  I had a chance to play one of your HBX - AC15  amps recently and I was very impressed.  I've always thought of the original VOX as sort of a one trick pony, but the HBX-AC15 amp just had a spectacular range.  The Negative Loop(NNFB) switch really proved to be much more useful (and less gimmicky) than I expected as well!  Dave D. 

Hi Fine Frenzel Friends, I’ve thoroughly enjoyed my recent Sweet Little 15 HBX-AC15 purchase. Though the clean channel is excellent, the boost side has an incredibly unique, but never odd or unusable, sound. I hear a bit of a blend between the Vox/Matchless sparkle/bite and the warmth of Fender Tweed. Reacts incredibly well with drive pedals, though the natural drive of the amp gets into wonderful fuzz territory when cranked. I’ve tried to put together a very brief video demo, since there’s not a lot out there on YouTube at the moment for this amp, so if you find this useful, feel free to use it however it may be useful: 

I plan to make a few more demos with the sound in a mix, since this amp sits so wonderfully with other instruments.  Thanks for making great gear at great prices. Will not be my last Frenzel amp. James Schlittenhart 


 Dear Frenzel Amp Team,  I am a huge fan and owner of your Deluxe Plus amp. I ordered a Sweet Little 15. I received the amp this weekend and was eager to finally unbox it today. I had to pry myself away from its side to unplug my guitar to send this reply. It nails the tones I am looking for and am looking forward to years of service.  Here are a few pictures of my Frenzel line-up. Thank you, again. Sincerely,  Larry K. (California)

HBX-AC30 - The HBX-AC30 amp you sent me sounds terrific, I'm impressed.  Thank you. Ryan K. (Massachusetts)

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