The new Coda S5.5 amplifier: It's a "Petite Beast"!

I have in-house the New Coda Technologies S5.5 amplifier for review for Stereo Times website. It will be awhile before I write the review. However, I'm so impressed by the performance of this petite amplifier, it only weights 45 pounds, that I wanted to give a heads up to you GON members if you are in the market for a balanced pure class A amplifier, delivers 50 watts @ 8 Ohms, and can drop 100 Amperes of current on a peak!

The world class build quality of Coda amplifiers is on display with the S5.5, along with the most beautiful purity of tonality, precise sound-staging, complete liquidity offered by pure class A design, and what might be the best top end regarding details, decays, and a natural shimmering without brightness or any edge at all.

The S5.5 uses extremely wide bandwidth output transistors instead of the usual TO3 devices used in most transistor designs. I own the Coda #16, which is great, but the midrange/high end is taken to another level of musical enjoyment with the S5.5. The S5.5 has a sense of speed/aliveness that is exciting to listen to that you experience in live music. The amp is dynamic as hell, has driven with ease any speaker I have tried it with, hence my nickname of the "Petite Beast". Remember, 50 watts pure class A, can drop 100 amperes of current and only weights 45 pounds.

Teajay (Terry London)


Hey grk,

You did not highjack the thread, just sharing information about other's opinions/experiences with D amplifiers. Yes, indeed Dr. Bump raved about the pair of AGD amps he had in for review. Yet, I have listened to AGD's Vivace MKII amps and at best thought they were competent, nothing special or extraordinary to my ears. Of course this boils down to personal taste and system matching. No right or wrong answer. However, I know at least three buyers of AGD amplifiers who regretted selling off their Class A amplifiers and did not get connected to the music with the D amplifier. Obviously, the Dr. Bump had a very different experience compared to his VAC amplifier.



Dr. Michael Bump is a renowned musician and among other things, Professor of Percussion Studies at the Truman State University (Department of Music) and a Director at the Percussive Arts Society Board of Directors.

I guess the only regret your friends may have now, is the reduced heating in winter those CLASS-A amps provided that now have to be somehow provided by a more efficient means of heating generation, maybe a heat pump. On the other hand, maybe they will be happier in summer....personal taste of course.

@aw-agd @johnah5 

Dr. Michael Bump is a renowned musician and among other things, Professor of Percussion Studies at the Truman State University (Department of Music) and a Director at the Percussive Arts Society Board of Directors.

I guess that changes everything.

My CODA S5.5 just showed up late yesterday, and I unpacked it this morning. What a gorgeous beast it is, mine is silver with gold buttons (both are available choices). It is moderately heavy but actually manageable, huge heat sinks, oozes quality, and I didn't expect the WBT highline connectors.

I'll put it into place of the Denafrips Thallo amplifier this afternoon, and allow it to break in along with the Clayton Shaw Caladan speakers. I'll try to get some early thoughts together in the next day or so.

Hey vthokie83,

Congrats! I truly believe you are in for a great sonic treat in the next couple of days. Please, let us know what you think when you get a take on the S5.5 in your system.


Dr. Michael Bump is a renowned musician and among other things, Professor of Percussion Studies at the Truman State University (Department of Music) and a Director at the Percussive Arts Society Board of Directors.

A professor of percussion studies, I am sure the ears are in great shape.

I had a S5.5, purchased from Mike at Audio Archon. Great guy to deal with. Had the newest and improved transistors according to Doug Dale.  While their website and documentation leaves much to be desired, Doug answered all of my questions and concerns in a timely and respectful manner. It sounded very articulate, clean and detailed and easily drove my Selah Audio Ceramica speakers (6 nominal 4 minimum, 88 dB), however, musically it just never got my toes tapping. Beautiful amp, great build quality, never got more than a little warm, great confidence in its reliability and potential longevity.

But I believe it would have sounded much better with a solid state preamp instead of my BAT VK-51SE tube preamp. Its XLR input impedance is only 10kOhms, so most likely too low and not a good match for an XLR tube preamp. Just wanted to point this out to anyone potentially considering use of this amp with a tube preamp. It sounded better with my Lyngdorf MP-40 as the preamp, but not even close to the overall fidelity level of the BAT tube preamp with the 2 amps I tried with over 100 kOhm input impedances. So I sold it to TMR and it sold within a couple of weeks. Of course, your results may vary with your tube preamp, but I can say, unfortunately, that I found it to be a mediocre match with the BAT tube preamp.

Doug is a great guy. Really enjoyed all our conversations. 

He made it known to me that he's not to fond of tube gear. I've been having tje same issue looking for a balanced tube preamp..  that 10k impedance is usually low. 

Side note.. every discussion i find on different platforms..where CODA is discussed they are always polite and informative. There are a lot of toxic people I'm this hobby and reading through this discussion is a breath of fresh air. 


Fair point about the input impedance on XLR. I've already had this conversation with Aric Kimball of Aric Audio, who is building a Motherlode XL preamp for me. He is modifying it to work with the low impedance of the CODA S5.5.....I believe he is adding an additional 1.0uf cap to compensate.

iovi66 and tmac1700,

       Your comments are very much appreciated and I second both your comments on Doug Dale and Coda. I had a lengthy phone conversation with Doug Dale a couple of days ago. I cannot praise Doug and Coda enough. Doug is a pleasure to talk with, so knowledgeable , possessing exemplary ethics and integrity! I am so thankful I tuned into this company and certainly Terry London and James of Destination HiFi were very influential in my decision.

       I am now trying to decide on adding a Coda No.8 or S5.5 to my current CSiB and control either with the internal ss preamp (07x topology based) in the CSiB. I was initially leaning to the S5.5 and I believe it should perform very well only in talking with Doug,  the topic of current came up for my maggies and possibly a set of Totem Acoustic speakers I am considering. Doug's views are  steering me more in the direction of the No. 8 and he is right on the advantages of  the CSiB essentially controlling twin No. 8s over an S5.5 and a No.8.  You can't go wrong with either amp though, only I may want to experiment with my ARC SP-8 tube amp and not so sure it's going to have as a good a synergy with the S5.5 as the No.8.

        Final decision on this not made yet and in no hurry.  Any comments on tube preamp synergy with the S5.5 and No.8 are factors in the decision process, along with the need for more current with some of my speakers. I see vthokie83 is proactively having AricAudio modify the Motherlode XL tube preamp, so his feedback on that will be interesting. For every problem there is a solution; it's finding it that's the challenge.  Thanks again all, joe 


        I am very interested in your feedback on the S5.5's with the Caladan's. It should be Stellar! What is the preamp section? Thanks, joe


The CODA S5.5 just arrived and installed today, I just turned it on all day and left it to settle in with no listening.....I'll do a little of that tomorrow. The Caladan's are only a little over a week old, but sounding great. I did leave a rather detailed post on my initial listening thoughts if you want to look that over; though those thoughts were with the existing Denafrips Thallo amp.

Until I receive the Aric Audio Motherlode XL, I'm using my current Denafrips Hades SS preamp

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Thank you for your reply and we’ll patiently wait for your S5.5 and Caladan’s to settle in. Looking forward to your review comments on both the S5.5 and Caladan’s, as well as the Motherlode XL down the road.

Not sure if you have any experience with Klipsch quasi horn speakers such as the Heritage line Forte 3, 4 or Cornwall 4. If you do, my interest in your opinion as to how the Caladan’s compare isn’t a matter of which sounds better to you as they will be definitely different, but more of what you feel are their relative strengths and weaknesses. Understandably, this is only possible if you have had some experience with the quasi horn speakers mentioned. Thanks again for your comments on the S5.5, Caladan’s, and the Motherload XL, as all three are on my ’candidates of high interest’ list! Thanks again, joe






Hey Joe,

Wish I could answer your question about how much current the AGD amps drop into different loads. However, I have never seen that spec on any of their different amp models, As we both know Coda has some of the highest ratings of current loading on the market which contributes to their superlative performance and ability to drive virtually any speaker effortlessly.



My only experience with Klipsch speakers is in other people's systems, and I've mostly been unimpressed.....but that may very well be the accompanying electronics. Twice they were being driven by a "mainstream" amp (can't remember but Technics/Onkyo/Sony/or the like). The one time I was impressed, my friend was driving a pair of Cornwall IIIs with a Tubes4hifi VTA ST-120 tube amp......which I later purchased and still own. But I don't own Klipsch and certainly have no extended experience with them.


The information about the maximum current capability of all AGD amps is available on the AGD website under each product description.

Audion, Vivace and Tempo : 30Apk

AGD Gran Vivace and DUET :  50Apk

AGD Solo >70Apk


Im currently using a Coda CB preamp with the No.8. It sounds good but its very neutral in my opinion.

My goal was to get a neutral power amp and let the speakers do their thing and tweek the sound via preamp. My goal was to find a truly balanced tube preamp preamp to pair with the No.8. But with the No.8 having only 10k input impedance balanced. I’ve been having a really hard time finding something to match. I recently came across another low key brand. Backert Labs Rhumba. Made in USA. He has three preamps.. balanced and all three have an output impedance of <75.

. I believe the price ranges from 4000-12000. But you’d have to check his site. Either way.. if you already have a tube preamp that you want to try with whichever amp you decide can’t hurt to try. Doug did say he builds his amps with balanced in mind.. but I’m sure using the single ended is just as good.

Im curious to know why Doug’s amps have such a low input impedance..when using balanced. I guess it doesn’t matter when using a solid state pre amp.. But I’d still be curious to know why. I just don’t see it on other amplifiers.

Sounds like you can’t go wrong with either amp. I’d trust his judgment..I’m wondering why Doug is steering you to the No.8 though. 

As far as I have been able to discern, the general rule of thumb for proper impedance component matching is that the input impedance should be at least 10x higher than the output impedance. Given that the input impedance of the Coda S5.5 is 10K ohms, then one could at least theoretically have a preamp with an output impedance of up to 1K ohms and still be okay. Have people found this to be true or should one strive for even lower output impedances, like 20x or more?

As an example, I noticed that the Atmas-Sphere Class D amps have an input impedance of 100K ohms while their tube preamps have an output impedance of 250 ohms. That's quite a "cushion"!

@vthokie83  I too am interested in your comments on the Caladan / s5.5 pairing. I have Caladans. Currently a pair of AGD Tempo’s as mono blocks, using one channel of each amp - not bridged (don’t ask ;-). 

Regarding tube preamps, I have a Backert Labs Rhythm 1.3 which has an output impedance of < 80 per their specs. Doug at Coda said they would play well together.

There is absolutely nothing wrong with the AGD / Caladan pairing, but sometimes you don’t know what you are missing until you aren’t. Call it curiosity on my part. Or neurosis if you wish.

Markmuse, I never did see anywhere that you posted your opinions on the Caladans since you got them.....I'd love to hear from you on them. Send a private message if you don't want to hijack this thread.

I loved the Backert Labs Rhythm 1.4s that I test drove a few weeks ago, it came down to those and the Aric Audio Motherlode XL for me.....but the Backert was absolutely terrific.

I'll try to get some thoughts together on the CODA/Caladan pairing, but it's 73 degrees and sunny here in Chicago today....and my wife has me cleaning up around the house today (and basement). She's definitely putting a "hitch in my getalong"....but she never complained about buying the Caladans/CODA/Aric Audio, so I owe her.

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Buy a 07x and call it a day. I use the 8 in tandem with the 07x and I couldn’t be happier with the combo! 

@vthokie83  The Caladans take a very long time to break in. They tend to be a bit sharp out of the boxes. Once they settle in they are great. I am replacing a pair of Fyne F1-8 that with stands cost more than 3x. Really great imaging, great depth of textures, very musical. They are, at least in my system, ‘you are there’ speakers. The Caladans will reveal every little change upstream, so play with different cables, interconnects, power cords.

in the Backert I am using 12sn7 tubes with adapters. These kick it up to another level.



We posted this info before on this thread.

The information about the maximum current capability of all AGD amps is available on the AGD website under each product description. We do not consider any technical characteristic of our amps remarkable or not remarkable and we do not use them as a marketing tool, they just are what they are.

In any case specifically for your question:

Audion, Vivace and Tempo : 30Apk

AGD Gran Vivace and DUET :  50Apk

AGD Solo >70Apk


Thank you for the information on current for the AGD Class D amps. I was just curious and actually those current values are quite excellent for Class D topology imo. The AGD amps do look to be excellent instruments getting great reviews. Thank you again.

I recommend the Holo Serene preamp or the Benchmark LA4 preamp with either the #8 or #16. They replaced the CODA 07x preamp on my office system. The Serene is a bit warmer than the LA4. They really make the amps shine because they do not add to the already great sounding amps.

Hey Guys,

Just got off the phone with John, who purchased the S5.5 last week and has spent a lot of time listening to it. He is extremely happy with the results compared to his reference tube amplifier. Overall a beautiful silky smooth presentation, airy extended high frequencies, deeper more controlled bass then his tube amp, a mid-range that he describes as very tube-like, and finally a sense of aliveness/energy that is quite exciting to him and his wife on their favorite music. I believe he uses a tube line-stage in his system to drive the S5.5.


Does anyone have recommendations on a tube pre that matches well with Coda amps? Mainly preamps that are or offer balanced.

Hey christianb5s4,

I recommend you give a call to Mike Kay (Audio Archon) who will give you the specs necessary for a tube based line-stage to optimally drive the S5.5 or the other Coda amplifiers. 



After much consideration I looked at several tube preamps: Backert Labs Rhumba Extreme 1.4, BAT VK-80, Rogue RP-9, used Audio Research REF 5SE, and Aric Audio Motherlode XL....and had previously looked at Atma-Sphere MP-3, LTA MircroZOTL, along with a few others. The LTA MircoZOTL does not have XLR outputs, but does have XLR inputs.

I found the Backert Labs Rhumba Extreme and the BAT VK-80 to be favorites, thought the BAT was out of my price friend however did buy one.

One thing to consider is that the CODA S5.5 has an input impedance of 10K Ohms on it's XLR outputs....which can be troublesome. I ended up purchasing the Aric Motherlode XL preamp, and Aric is modifying it's circuit to work with that 10K Ohm circuit. The Motherlode XL has 2 sets of XLR inputs, 2 sets of single ended RCA inputs, one XLR output, and one single ended RCA outputs.

I'd reach out to Aric 413 627 2543 to have a conversation about the S5.t combination, he's a GREAT guy to talk to, and is very helpful. I know he's created several Motherlode XLs for clients that will end using them with CODA S5.5s.

I also purchased my CODA S5.5 from Mike Kay at Audio Archon, he's also a great guy to talk to, and carries several tube preamps.

+1 on the Aric Audio preamp.  I used an Aric Audio preamp with my Pass Labs XA-25, and it was a great, musical combination; wonderful match. I have since sold the Pass, and replaced it with an Aric Audio 300B PSET tubed amp, and the combo is magical! Highly recommend Aric's gear! 

I’ve been wrestling between the Aric Audio Motherload XL and Beckert Labbs Rhumba. They both seem like a good match to pair with a Coda amplifier. 

I recently sold/traded a Pass 250.8 and an XP-22, and took a Coda Csib V1 Integrated amp in trade with cash. I was downgrading and just trying to recoup some cash. I had no experience with Coda, but had read about them for years. The guy I traded/sold with raved about the Coda Csib V1 and said it was a great match with my big Harbeth's. He also has Harbeth's.  My impressions....I'm extremely happy. This is a fantastic integrated amp. Extremely detailed...actually i think more than a 20K Pass combination that I sold. I think the Pass combination is a bit smoother/musical, maybe quieter, but the Coda Integrated is no slouch and I'm very happy with my trade.

BTW- Before my above system...I had a Pass Int 60...which I had no complaints..The Coda beats the Pass Int 60 easily...


If you have the opportunity, I'd suggest you find a Backert dealer and audition both the Rhumba 1.4 and the Rhumba Extreme 1.4....I think you will find a pretty big difference. The Rhumba Extreme 1.4 is very close to the $13,000 flagship Rhythm in a Rhumba case; Backert confirmed that opinion when I spoke with them.

I found the Rhumba 1.4 was a really nice preamp, but the Rhumba Extreme 1.4 was world class. My opinion is that the Motherlode XL will easily outclass the base Rhumba 1.4, but the Rhumba Extreme 1.4 will give it a run for it's money. I was able to find dealers willing to price the Extreme 1.4 considerably less than the $8,500 list price.

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Hey vthokie83,

Both the Backert Labs and AricAudio preamps are great pieces and Andy and Aric are first rate gentlemen. I have owned and reviewed preamps from both companies. The Backert Labs,using 12AU7 tubes, and AricAudio, using 6SN7 tubes offer a different presentation. The Backert Labs is lighting fast, quite detailed without being etchy, very transparent, and very pure in tonality. It reminds me very much of the Linear Tube Audio's David Berning sound. The Aric Audio offers those virtues, but because it uses 6SN7s its midrange  is fuller and a bit more romantic. It really comes down to personal taste and system matching. I personally love the sound of1940's NOS 6SN7 TungSol black glass oval plates in my Motherlode preamplifier.

Because the S5.5 is so transparent you will hear the "flavor" you inject into the system using different preamplifiers or the tubes you select.



I didn't have a chance to compare the Motherlode XL with the Backert, but the Backert Rhumba 1.4 vs the Rhumba Extreme 1.4.....that's why I suggested the demo between the two if near a dealer. The Rhumba Extreme 1.4 would have been my choice had I not gone with the Motherlode XL.

I'll have some short listening notes on the CODA S5.5, I've been able to get about 10 hours listening on it so far.

Hey vthokie83,

Please do share! I'm quite interested in what your experience/take will be on the Motherlode/S5.5 combo.


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The benchmark I don’t feel has much meat on the bones .

Krell is a name o watch they have some new models coming out by June 

thierksa 400 is incredibly good but Waay too expensive ver $30 k 

I am told a smaller version  around $13 k is coming out .

a ksa integrated. Would be also great .

@audioman58 Have you heard the KRELL KSA i400? I have an amazing offer to trade-in my CODA #16 for that amp. I owned the KRELL Duo 175XD and loved it. Moreso, then the CODA #8. I think the #16 has the edge over the 175XD, mainly with power.

Do you have a link to the information on the new KRELL models? A smaller version of the KSA i400 at $13k is in line with what I am considering next for my Livingroom,

- CODA #16 or S5.5 monos

- SimAudio 761 North Collection


I moved my CODA #16 to my office, and it is incredible with the Magnepan LRS+ ($1000). I am keeping it there and need an amp for the Livingroom.

I am waiting to hear back from my CODA dealer about the S5.5 and running it in mono vs the #16. Anybody have an opinion on that?

Maybe I should call Doug at CODA .


I have heard their ksa 400 it is exceptionally good ,but much too expensive for me. 
my dealer friend casually mentioned these new products. You will not hear about them until they are fully tested li cannot say exactly if they are running on their June release date or waiting until the fall for the Audio shows. I also am very curious.


Give Doug Dale at CODA a call, I spoke to him a few times and he was helpful and great to speak with before I bought my CODA S5.5. I don't want to speak for him, but I think he'll suggest the #16 vs bridged S5.5s

The Audio Hungary Qualiton C200 tube preamp is a true balanced design and that is what I use to drive my S5.5 - I am getting solid, articulate bass, pure, resolving midrange and sparkling high frequency extension. Wide and especially deep soundstage. Speakers are Mofi Sourcepoint 10s with Inakustik cables. I paid $5.5K new for the preamp so it's not expensive. It was a recommended pairing from Al who owns Hifi Art in Winnipeg (we're in Canada), google the website it has a list of what he carries.