Coincident Frankenstein mk.2 amps

Has anybody heard them with Druid V speakers? Do you think they will have enough power? I listen to mostly jazz, but also blues, rock, and classical. My listening levels are around 75 to 95db.
Germanboxers uses this amplifier with his Zu DEF IV. Send him an audiogon email for his thoughts.He`s a very experienced listener.

I run a pair of Zu Audio Essences with my Manley 300b amplifiers. I run my amps single ended, meaning they put out 11 watts. The Essences are not as efficient as the Druids, still, the Manley amps drive them with gusto. You should not have any problem driving the Druids with the Frankensteins. You should be able to listen at your preferred volume levels and still have plenty of headroom left.

I don't know if you have considered this, but I strongly suggest you acquire a Zu subwoofer with the Druids. I use a Zu Mini-Method with my Essence speakers. Zu subs are lightning quick and integrate seamlessly with speakers. My Mini-Method sub is an integral part of the system. It is key in delivering a full spectrum presentation of the acoustic image. I could not live without it.
With your speakers and listening levels you`ll hardly use more than one watt and very often much less power with these high sensitivity Zu Druids. My speaker is 94 db sensitive(less sensitive than yours) and volume,scale and driver control are not an issue with the Frankenstein(and I came from using a 100 watt PP tube amp).This 8 watt SET has excellent transformers and power supply design.
Thanks Charles and Iramirez.
Yes, I use a Undertone sub and the pairing is excellent. IMHO, the sub is almost mandatory. The deep bass of course is better, more importantly the tonal balance is fuller and more fleshed out. The soundstage also opens up nicely and the sound is effortless.

I'm using a First Watt J2 amp which sounds wonderful. I love female vocals and I am hoping the 300b amps will give me that spooky real palability.

Thanks for reassuring me they will drive my speakers with aplomb.
Charles, if I decide to purchase them be prepared for me picking your brain and which 300b to use. ;)

Hi Joe,
I`ll be glad to share my 300b tube rolling experiences with you. I`ve had the good opprotunity to hear a fair number of them.The Frankenstein is exceptionally revealing and exposes the differences quite easily.Although it is full body,natural toned and open,its not a warmish,dark or colored SET amp at all.
Hello Snopro, I held off of being the first respondent to your thread. I was not sure if you already had the speakers or the amps. I did a quick web search of the Druid V. By my research, I could very happily live with them!! I would assume that your proposed match with the Franks would be very musically fulfilling!!! Of course, my amplification choice is slightly better.... but who is splitting hairs? HA (kidding)
Hi Snopro,

I have used the Frankensteins Mk2 with my Zu Def Mk4's for several months. The Franks were revelatory for me in this system. I was using Atma-Sphere M-60's. The tone density, palpability, 3D imaging, micro dynamic shadings, and overall coherence (space and musicians cut from a single cloth) were all improved. Transparency is also very very high. Unless you routinely hit peak SPL's greater than 105, you won't even think about not having enough power. I'd be far more worried about hearing loss if those SPL's were normal for your listening sessions.

The Franks are top notch amps (and extraordinary values) that I would continue to use if only I hadn't stumbled on a little better match for my system, Audion Black Shadows.
Your situation is a perfect example of the first watt sound quality princciple.Given the high efficiency of you speaker and preferred listening levels(which are very realistic without risking hearing loss).Much of your playing will be drawing only fractions of a watt( when you listen in the 75-85 db SPL range).The Frankenstein sounds beautiful in this low power range,very pure,organic, nuanced and completely transparent.Some amplifiers struggle in this low power region(closed in and congested).Germanboxers summed up the Frank`s attributes very well as usual.
Thanks everyone! Waiting on the gentleman from Audio Loft in Manhattan
to call for an audition. He said in couple of weeks after he relocates.
I'll let you know what I think.

It's good you get a chance to audition the Frankenstein. I bought mine
direct from Israel Bloom unheard prior to the purchase 4 years ago. It
worked out fine to say the least. It was love at first listen and my admiration
and joy has only grown. Good Luck.
Has anybody heard the new psvane 300b-t mk.II tube in their amps? How
do they compare to the EML 300b XLS?
I spoke to Israel the other day. He said the amps now ship with the clear
glass Psvane's and sound very good.

If Israel uses the Psvane now it must be quite good (I've not heard this one). I can tell you that the EML XLS sounds fantastic in my Frankenstein. Powerful, dynamic yet very organic and involving. Likely can't go wrong with either tube.
Hi Charles,
Does the EML render vocals with lifelike presence?
I went ahead and just ordered the Frank's without hearing them, but from all the feedback and fellow audiophile opinions I'm sure I'll love them.

Thanks, looking forward to receiving them!
Hi Snopro,
Congratulations on the Frankenstein purchase, I think you'll be very happy with it. The EML XLS has been an unexpected surprise for me. Yes it has a very good reputation and I thought it would sound well in my system. The result bettered my expectation, it mates beautifully with Frankenstein and is a joy to listen to . The music just flows. Vocals and everything else are reproduced wonderfully.

Snopro, the high quality 300b tubes bring out the best in the Frankenstein. These better tubes aren't cheap but honestly this amplifier is worthy of
them. Israel is a no nonsense guy and candid so I believe that the Psvane is a very good match as well. The splendid Japanese Takatsuki-TA 300b has been my very best choice for the Franks but they're so darn expensive (1800-2000 per pair). The EML at 685.00 is by no means inexpensive but relative to the Takatsuki they are.The Takatsuki is pure organic bliss with excellent dynamics and everything else thrown in. The EML is a"bit" more dynamic and not quite as organic-fluid (but surprisingly close). The EML XLS is a exceptional value for a truly premium 300b. Takatsuki is the ultimate price be dammed choice but it doesn't embarrass the EML performance, no sir!

The AVVT 32 SLis another top tube but are no longer made and very hard to find.
The Sophia Royal Princess sounds excellent in the Franks also, at 1200.00 I cant say they're better than the EML XLS.To be fair I didn't have them together at the same time to compare.
Any of these top tier tubes will allow the superb Franks to just sing toits full potential.
Thanks Charles for all your input! My first tube purchase will probably be the EML's. Where did you get that price? The price I've seen is $720.

Once I have some time on the amps and extra money put on the side, I'll spring for the takatsuki's.

Thanks for all your help!

Hi Joe,
I purchased mine about 5 months ago (just getting around to using them recently).They came from tube the price has increased since then unfortunately. Still a bargain relatively speaking. George offers very good service, I'd buy from him again.
I received my Franks to other day. I have around 15 hours on them the sound is pretty good. How many hours before it fully opens up?

Hopefully, the soundstage will expand both in width and layered depth and the sound will really flesh out, as of now my First Watt J2 sounds much better.

I am using the EML 300b XLS tubes. On my amps the 300b sockets ( big pins face the back) make the front of the tubes face the back of the amp.
Is anybody else's that way? I would like it turned around, so you can see the light and nice label.

Joe be patient, these amps need roughly 200 hours to burn in. They will steadily open up.The tubes need some hours also.Germanboxers and I gave you our honest opinion, we both find the Franks wonderful. Too early to say but perhaps you may not feel the same. These things are impossible to predict.The First Watt amp may suit you more but I`d avoid rash judgements.If you search the archives, the Franks are nesrly always praised and admired. No component will please everyone all the time.
I'll be patient, Charles. No knee jerk reactions, just giving my first thoughts.
The amp is very quiet and the sound is grain free,which is a good think.

After all these years I know it will get better, just wanted to know how much better.
Joe ,
Believe me I understand.I thought the Franks were"good" right off the UPS truck and they just kept improving with time.Your First Watt J2 amp is a different sound but makes a very good reference point.I moved from a 100 watt push pull tube amp, again diferent sound for sure.
Best of Luck,
One thing I have been doing lately is using the 16 ohm tap instead of the 8 ohm tap, my speakers are 8 ohm. Changed the sound quite significantly. Much more separation. I'm not saying it's better but definitely work trying. Israel Blume says it has no detrimental effect on the Franks.

Speaker tap preference is trial and error, you don't know until you try. My choice is the 16 ohm tap (more open, spacious and dynamic). My speakers are a 14 ohm load so that likely explains my results
Ok, with more hours logged in the amp is starting to open up nicely! First off they drive the speakers with plenty of power. They are dynamic, fast, transparent, and extended at both ends. No warm fuzzy rolled of sound here. Tonal balance is very good.

The EML XLS are very extended and linear, hopefully they will get a little warmer with more hours on them.

The amps still need some more time, but are improving steadily. The midrange hasn't yet fully developed that palpable presence I'm looking for. I'm sure once the amps are fully broken in and some tube rolling in my preamp,I'll get there.

Did anybody try different 6em7 and 5u4g tubes? My amps came with Raytheon 6em7's and RCA 5u4gb tubes. The RCA's were structured a little different from each other. One was taller and had a side getter the other was shorter and had a top getter. I put in my taller black plate straight glass 5u4gb tubes and got a little better focus and the highs became airier.
Hi Snopro,
This is the normal break in pattern and it will continually improve, there's substantially more to come. Remember that those superb transformers Israel chose simply need sufficient time, this is a gradual process. The EML XLS tube gets better as well. This is a very neutral 300b, but you'll gain a bit more warmth with additional playing time. There are warmer 300b tubes available but the EML will reveal the true tonal color and body of instruments without embellishments. It's a great match for the Frankenstein as both are transparent, , uncolored and very honest (but not clinical at all). You'll get the pure organic character and realism without the gratuitous fluff.
I haven't changed the 6em7 tubes (not many choices available). I've tried the RCA and Sylvania rectifier tubes and there's little difference. The intriguing rectifier for me is the EML 5u4 version. Good comments are made about it but they're very expensive (they're very large tubes as well).
Yeah, those EML rectifiers sure look pretty. Maybe somebody on the forum will let us know how they sound.


I use the EML 5u4g. Gorgeous tube at night (meshplate as you may already
know) and yes, it is huge.

Sound: In my 300b SET, I think they are among the best I've heard. I also like
and use vintage RCA's. Can't speculate how they would sound in your Franks.

5u4g and 5u4gb are slightly different. Some amps can use either, some can't.
Make sure yours can if you decide to get a pair.
Yes, it is a gorgeous tube when lit. Thanks for the heads up!If I'm ever ready to purchase, I'll make sure it's compatible in my amps.
Hi Onemug,
I`m begining to understand your admiration for EML tubes.The more my EML XLS accumulates playing time the better it sounds, I`m truly enjoying this tube steadily more as time passes by.It`s powerful and dynamic yet has refinement and suave musical grace.
Update: I have around 150 hours on the amps and they are sounding much better! They opened up nicely with a refined natural tonal balance, good separation and layered depth. Bass is tuneful and goes pretty deep, very good for a SET amp. The midrange is starting to really sound organic with nice flow. Highs are extended,airy, with a natural decay.

Notice I keep using the word natural, because it is the opposite of cold, dry, thin, grainy, sterile, hyper detailed sound. Don't misunderstand and think the amps are slow, syrupy, and lacking detail. Further from the truth, it just portrays acoustic music in a natural believeable way.

They are keepers and supposedly will get even better with more time!

Hi Joe,
I'm glad you remained patient and allowed the Frankenstein to burn-in and
evolve as it naturally does. Those custom transformers really need time to
open up and demonstrate what they're capable of. Your overall impression
is identical to mine in that the key terms used to describe what you hear are
"natural", realism, presence and organic.

The news gets better as your Franks are going to improve further regarding
opening up , nuance, dynamics at all levels and become even more organic
and effortless in presentation.
I was very interested in your response to the Frankenstein in that your
reference was a First Watt amplifier (exceptional amp) and I knew there'd
be a different sound/presentation. The question would be which do you
prefer and which one connects/involves you more emotionally to your
music. The Frankenstein is truly a superb SET 300b amp and I'm happy to
read it worked out very well for you. You can't predict what someone else
may like regardless of how much joy a component has given you. You
have to listen and judge for yourself.
Curious, what is the ohm load of your speakers and are you using the 8 or the 16 ohm tap?
I tried both and preferred the 16 ohm tap (each requires some breah in) this will obviously vary depending on the speakers in use.
Did you audition the Decware Tori amp in your system?
My speakers are 16 ohms. I'm using the 16 ohm taps.
I first ordered the Decware, but cancelled the order for the Franks.

People who have them love them, personally I haven't heard them. FYI
Decware is coming out with a Torii IV.
That's understandable, my speaker is a 14 ohm load. The sound is very good with the 8 ohm tap but becomes even more dynamic,alive, engaging and dimensional when connected to the 16 ohm tap. The sense of ease and flow are increased.
What were the main differences you noticed or had to accommodate /
adjust to between the First Watt(25watt SS) and the Frankenstein amplifiers
(8 watt tube) if any ? Very different designs that I find interesting.
Hi Charles,
If you mean main differences in sound, the two amps don't sound vastly different. The First Watt is Class A single- ended using Jfet output transistors, which is a pretty rare bird.

The amp circuit acts somewhat like a tube amp. The amp loses half it's output at 4ohms & 16ohms. With my Druids V I only have 13 watts of power, which was plenty.

They are both lively engaging amps. The J2 goes deeper and has more slam. The Franks have better texture.The leading edge is more pronounced but does not have the sustain of the Franks on the trailing edge. Midrange is pretty close. The Franks are more liquid sounding with more air. Both amps have excellent treble. I think the Franks with the EML 300b XLS tubes gives a little more extension and refinement. The J2 has a touch more grain.

They both throw a wide deep layered soundstage and have excellent see thru qualities, which extracts very fine details and you can see deep into the soundstage.

I really enjoy both amps and will keep them both. Hopefully with more time the Franks midrange will flesh out even more. Would love to hear the old WE 300b & your Takatsuki's.

Can you tell me what is the fuse size? I would like to upgrade the fuses.

Hi Joe, thanks for sharing your impressions of these two fine amps. At 150 hours your Frankenstein will gain some gradual but noticeable improvement. The Takatsuki, Sophia Royal Princess are a "bit" warmer sounding and likely so is the Psvane WE Replica. I find the EML to be an excellent top to bottom tube with exceptional drive and dynamic abilities(still organic and not analytical). It plays to the strengths of the Frank's openess, tansparency and lack of colorations. Israel really likes the Psvane so it must be very good.
Joe I'm not home right now but believe the fuse is 3 amps, slow blow and the short length version. The fuse is very essy to access on the rear of the amp.
Charles, I'll give Israel a call mine look like 1.6 amp, but it's hard to make out.
Hi Joe,
Did you ever try different fuses in your Frankensteins? I hope the amp turned out to be what you were expecting.
Hi Charles,
Yeah, I put AMR gold fuses in. It was a worthwhile improvement. I'm loving
the amps, after 35 years in this hobby I finally am really content with my
It sounds so natural, organic, and so full of life. I stopped analyzing and
just enjoy the music. I'm in a good place right now,thanks to you and others
on this forum!
I played around with different rectifiers and like the tung-sol 5u4gb and
sylvania 5931 the best. After the holidays I'll try and spring for the
Takatsuki's, but the EML 300b XLS are very nice.

"I stopped analyzing and just enjoy the music" Joe, you couldn't have summed it up any better than that. If you get the Takatsuki you'll be very pleased but I've really come to realize how good the EML XLS is. The truth is that you can't go wrong with either of these fine tubes. Regarding fuses, the Synergistic Research Quantum is an excellent replacement in the Frankenstein. Good to know the AMR works out well also.

Thank you for the useful discussion about the tubes on the Frankenstein Mk ii. I just want to add my 2 cents because I had chance to try some rectifiers (RCA 5U4GB, Tung-sol 5U4GB, and EML 5U4GM), and output tubes (Psvane 300BT, 300BT-II, EML 300BM, and Takatsuki TA-300B).
To my ear, the Tung-sol/Takatsuki was the best by far out of all the combinations I have tried.
Rectifier: the RCA 5U4GB was the close second. As for the EML 5U4GM...I don't know... it added little more bass to my system, but that was all. It immediately killed three dimensionality, dynamics and transparency which had been easily conveyed by the Tung-sol.
Output tubes: In my system, the sound from Psvane was fast and nimble which I enjoyed. EML 300BM added more liquidity,musicality and authority in the bass, but it was not my cup of tea-little too slow. Takatsuki? As soon as putting them into the slots...I immediately talked to myself; That's it. Beautiful texture in every frequency range, significant musicality, no artificial exaggeration at the bottom (which I felt from EML 300BM), but still fast and tight notes with excellent tonal balance. I think this is the very best.

By the way, have you ever tried HiFi Tuning Supreme fuses for the amp? I would appreciate if you can give me any comments on that. Do you know the specfication of stock fuses?

Hi Wu,
Thanks for your impressions especially regarding the EML rectifier 5u4g. I
have thought about it but hesitated due to the cost of them .
We all hear differently as has been said many times. I really admire the
Takatsuki ( that's no secret) but in my system the EML XLS just shines and
competes with the Takatsuki closely. I don't hear the short comings you
point out. I'm happy to have both as well as the AVVT 32b. All three make
beautiful music in my Frankenstein. As far as rectifier tubes are concerned
I've used the Sylvania and RCA and didn't notice a significant difference.
Wu what speakers are you using with your Frankenstein? I've only used the
Synergistic Research Quantum fuses and they are an improvement in the
amplifier. 3 amp slow blow.
I wonder if any of you had any problems convincing your significant other that the amplifiers you were about to buy did not sound anything like their name implied?
Am breaking in a wartime Tung Sol 5u4g rectifier tube as we speak to be used with Sylvania 6SN7GT Badboys real soon. Speaking of fuses, anyone try the new Audio Magic Super Fuse? There appears to be several fuse manufacturers vying for the top spot...
Hi Wu,

I tried a few different rectifiers and liked the Tung-Sol 5u4gb and Sylvania 5931 the best. The Sylvania is a beautiful built tube.

The Pvsane hi-fi 300b which came with the amps weren't bad, but the EML 300b XLS tubes are much better. They are more extended in the bass and treble have a organic,lively, open, sound which is very engaging. They don't sound slow to me.
I would love to try the Takasuki tubes some day, but are very expensive.

I changed the fuses to AMR gold fuses which sounded a little more natural. Sorry didn't try the Hi-fi Supremes.

Did anybody try different 6em7 tubes?

Wu, where did you purchase the Takasuki tubes, can you buy them straight from Japan? You can answer on my system page if you like.

I'm very happy with my Franks!
Hi Charles,
Yes I definitely agree that we all listen to music in our own ways. Probable reasons I have the discrepant opinion on the EML were I) mine is EML 300BM (mesh), not XLS (I am not sure how they are different though), and ii) my ears are somewhat familiar with fast SS amps such as Soulution and Dartzeel. My current system is really simple. The Frankensteins are fed by DCS Vivaldi DAC and they drive Voxativ Amppeggio Signature. These are not most popular ones, but I am extremely fascinated by this 101dB, 11 ohm, single driver speakers. In my system, the 16 ohm tap is much better than the 8 ohm just like you said. While comparing those two taps, I felt the similar thing I noticed when I exchanged Tung-Sol rectifier to EML 5u4g. (if you are still tempted by the EML, you already know who is going to sell them to you Haha!) Thanks for the stock specification of the fuse.

@Isochronism Hahaha

Hi Joe,

Yes I bought the pair directly from Japan where one of my friends lives. I cannot say anything exactly because it seems the -XLS could be quite different than the -M, but the Takasuki is at least worthwhile to try in my opinion. Yes they are expensive...but we may have to spend much more money to achieve the same amount of improvements one can expect from the Takasuki-Just my thought.
My experience about the input tubes are very limited. Just tried GE NOS and Sylvania NOS, but didn't hear the difference.

Happy listening!
I don't believe that the 6em7 offers much in choice availability.
I thought you'd notice more organic sound from the EML as it acquired hours. It has what I'd call natural warmth rather than 'adding' warmth. The KR 300 XLS is definitely warmer but I feel that the EML XLS is the more natural and honest.
It has Charles, just compared to the Pvsane it has the qualities I described and I mentioned organic: wink.