Hi Ben,

From the bit I have learned about Sontecs, I would also agree that Sontecs are going to vary from unit to unit, especially in terms of how the older units were repaired and what adjustments/modifications were done to them. That is why I try to be cautious when describing a unit, or comparing it against another and why we must be detailed in discussing the EQ at hand as well.

In terms of modifications, I would say that in this case the Buzz REQ-2.2 was not modified for the sake of hot rodding the unit. These simple modifications seemed to have a positive impact on the Buzz itself and was a benefit I received from Matt's kind sharing of his knowledge and experience. I in no way would want things to be misconstrued as modifications being likened to a secret method of attaining a sound that is blissfully transformative over the original unit. I think the overall point of discussing these adjustments was to simply say there is a difference and that difference is more pleasing to Matt's and my ears. To give the reader an idea of what this difference sounds like, I felt the need to place it in the context of some other EQs and in descriptive terms that tried to generally capture the Buzz's impact on audio passed through it. As said before these EQs are all tools and each one has its own purpose and use and one is not a direct substitute for the other, nor an identical match. I'd also like to underscore that Lundahls are not some kind of magical device and that in this particular implemenation, alongside the other small changes, happened to work out and was something I looked into acquiring after having a detailed discussion with Matt and after doing extensive research on a companion EQ to the BPEQ.

Thank you Ben for bringing up the modification point, as I do find people get a little obsessed (for better or worse) in modifying gear. Sometimes mods work well, sometimes not and the owner of the unit in question has to determine what the goal is when modifying a piece of gear. It is also helpful when these things can be discussed with engineers and techs you trust, alongside the original designer of the unit.

Not at all but the culmination of all these changes have made an improvement over the original stock unit. That's all I'm saying.

Yes Ben that is correct! I replied to your question earlier regarding this in Post #403. It's all pretty straight forward stuff really but it all helps. Although I'm not sure using 'silver trace' wiring is going to make things sound better vs. copper but removing any unnecessary connectors, shortening the wiring runs as much as possible are where small improvements in signal quality & reliability can be made.

fwiw. . the Mu metal shields were implemented in Tim's design long before my last lot of mods. And yesss.. we've also discussed how the Lundahl's were added after Tim's new output cards. I don't see how any of that matters when the fact remains that it has made a significant improvement (along with the other changes) to the sound of the unit? Next time you're in Brisbane pop in & take a listen to this 'mystical' unit. Like the 'Sontec's' it's just possible that this Buzz actually sounds different to the one you demo'd. Don't forget that I was in favour of selling it for something like the Soma if the rebuilt REQ didn't do it for me. So I didn't have a loyalty to it and could've chosen to sell it but guess what.. it came back & kicked my 432 off top spot.

For the record mine was an MES-432C which had the original HS2000 cards in it so same as Adam's 482 re-issue except his opamps were new. I believe William Bowden's was the 430B with HS1000's. So that theory doesn't pan out.

This is true.. also age & maintenance plays a part in the sonic differences between each unit. But either way, the original units are universally "heralded" as the mastering EQ to own. The guy who bought mine used to work with them at Captiol Mastering and he was very happy with my unit saying it sounded the same as he remembered his old one so I don't think there was anything inherently worn out with mine as it was well maintained and had been recapped and sections of it re-soldered & the switches cleaned etc. not that long ago.

Didn't your Knif Vari-Mu come with Lundahl output transformers from factory?

Depends on the transformers used. The Massive Passive transformers sound muddy and closed in & we both preferred the unbalanced output on that unit so that's not a good example. Not all transformers are created equal & not all of them help whether it's part of the original design or not. It should be evaluated on a case by case basis. Disengage the technical part of your brain and what you've been taught about electrical design & decide for yourself.. does it sound good or not?

Well said Kevin, I completely agree.

That's also very true and worth noting. Lundahl's seem to work well for the Buzz REQ-2.2 & also for the Knif gear. When I used Chris Muth's suggestions to mod a pair of API550M's with Lundahl op transformers I didn't love the outcome. While it did sound rounder, I felt like they lost some of the tightness & punch which I preferred in the original circuit and what I liked in the API 5500 was the tightness of the 2520 opamps. So again depending on the unit & the desired effect it really does come down to trying things to see if you like them.

It's also worth noting that the decision to try transformers on the alt. output of the REQ was actually Tim's idea as his earlier output cards didn't seem to play very well with the Phoenix VariMu. So he designed a new output card which helped with impedance mis-matches and as a safety he also added the Lundahls to ensure that one set of outputs would resolve that issue. It just turned out that I also preferred the 'sound' of the lundahl outputs. Slightly bigger bottom end (even without EQ engaged), slightly less grainy & a nicer sound stage. All minor improvements but still worth noting.

Absolutely fantastic thread guys I've never seen such finesse and respect in a gear thread before. Refreshing!
I just wanted to point out that the difference between the traditional Lundahl and the Amorphous core Lundahl is substantial. Very little research into the performance of amorphous core xformers exists. This should be a consideration when arguing for the sound of particular mastering devices. Did Tim (Buzz audio fame) ever try these out? Just curious!

hi ben

would be great if you could tell me the exact type designation of the transformer.

btw: nice thread, great info's, thank you matt, kevin & ben!

Well there goes my HS 1000 theory. Good to know.

I had a another theory that what I liked about my Tube-Tech CL-2A (2 x CL1Bs) was the Lundahl transformers doing some subtle enhancing. I was fining the Phoenix a bit heavy handed for some things, and the Tube-Tech maybe a bit clean, so after some research the Knif Vari-mu was my choice. Turns out it was the right one! (always a relief when you spend thousands of dollars).

Part of the nature of Engineering is discovering how things work, and that part of my brain is always learning...why does something sound the way it does, and is it repeatable? So, the point I was trying to make in this thread is when discussing mods and what not lets make it open so we can all learn. There is a lot of smoke and mirrors in mastering, when I was an assistant everything was very tight lipped...there were not really any books or forums such as this.

Teebaum I'm not sure which output transformers Tim used, you would have to ask, he just told me about the circuit. The Knif design is quite different as the transformers are also part of the tube circuit, it's designed as a whole, that is the genius of his work. More info here:

Line Output | Lundahl Transformers

thank you ben

Wow, nice to see this old giant thread is still alive and kicking. As probably mentioned here some 100 pages ago, I also changed the transformers in my Knif Etip to Amorphous core Lundhals, had a chance to run some AB tests. No contest , def. a must do upgrade. I agree with the suggestion to put technical knowledge aside and open your ears wide instead. I also disliked the Manley transformers and much preferred the unbalanced outputs, same on Great River eq and on my Radial summing mixer with Jensens for example. Guess it's a matter of taste , transformers generally sound more "processed " to me, which of course can be useful. I have Helios clone mic pres made by Cyril Jones of Raindirk and have asked him to put output transformers in a separate box - I also use them with other equipment and make my decisions solely based on what sounds better for the job at hand. Nice to have these options.

As far as Jonte's stuff goes, the only thing stopping me from checking the Soma out is something I never thought would happen to me and it happens to partly be Jonte's fault. For several years I've been mainly working with Etip and SPL PQ (occasionally also EAR 822) and I still don't have the slightest desire to change or add another EQ.
Etip for broad strokes, almost always in M/S, PQ adding digital-like precision , all pots rather than switches (usual 0.5 db steps just not enough control, continuous Q and freq sweep make a huge difference to me). Both boxes with great sonics of course which is top priority and something I had been chasing for years prior to discovering this combo. Just reminds me how so much mastering kit lacks in musicality, claiming to be 'clean' and 'transparent' but actually just filtering out chunks of freq spectrum and losing dynamics. Transformers can easily do the job of an EQ and compressor together - great if and when it works but mostly I'd like a bit more control.
So, yes, "Not all transformers are created equal".

great to read this - i use a g14 & ordered a soma today, looks like a nice combination.

Just finished my first mix with the new SOMA and VARI MU II. They are insanely good sounding. Absolutely love them! Both are silky smooth and musical. Build like a tank as well.

My god that is gorgeous!!!! I have the older looking Vari-Mu II but I was assured by Jonte that it is the same design internally, although I have less options as far as settings are concerned. Congrats man, it's a great combo.

Hi Shelterr,

Based on your picture, I think the only real difference is I have an optional +6db Gain switch on the SOMA. The other differences are just slight diff layout on the switches, ie, bypass switch on the VARI MU II, and the color of the ON/OFF bulb.

I have uploaded few pictures showing the inside of the SOMA and VARI MU II here.

nOiz - a set on Flickr

wow, nice pictures!

my soma should arrive next week...

Mine is almost done. Just needs some knob covers.

what a beauty!

a little tip: use different colored caps for the gains than for the frequencies and q's.

I was chatting with joe Malone a year or so ago when I got a sontec clone and was enquiring about the hs1000 Opamps. Joe sells adaptors for the hs1000and the 2000 and knows the Opamps very well. He was telling me that for a time sontec would wup ship their processors with an extra h1000 taped to the inside case for when the hs1000 blew up / caught fire. I asked him how such a coveted design could be also a fire hazard - he told me that when they where looking for a new opmap for their 432c they hired a guy from the video industry who designed the hs1000 - anyway it was is a fantastic sounding opamp but with one drawback - it would catch fire at any time. It was overbuilt to the point that it could not thermally contain itself and would catch on fire. It was so high speed that flames where it's eventual end each and Everytime.
Proof that performance isn't the only consideration when making a critical design decision!

sweeeet!

i've also have a cl 2a (which i also find very clean for a tube unit, i guess the cl1b has a bit more charakter) & i know the knif pure mu & soma a bit from teebaum. i've also heard examples from the phoenix. teebaum had the pure mu first & it has quite a strong footprint - BUT: not in terms of saturation (as a e.g. phoenix or manley), but only if you put it into the chain, the signal gets improved, e.g. less harsh. i guess this makes the knif useful for a broader area.

first i thought that main contributing factor must be the lundahl amorphous core transformer. but then i heard the soma (which also has the amorphous core) i realized that this seems to be not the case, since the soma's footprint is more subtle compared to the pure mu's. so as you said, it must be the design.

from what i understood, he uses the transformers (by changing their configuration) for implementing M/S.

Who makes those knobs?

Nah, I like all black better ...less fatiguing on the eyes ;-)

maybe you need a eye doctor?

ELMA (Soft Touch)

https://gearspace.com/board/attachme...ouch-knobs.pdf

No, I don't think so.....it's just that I don't agree with your colour choices for knobs on mastering gear. Deal with it ...

Thanks!

don't let this end! :(

Any updates on the SPL or views
Thanks

Not sure exactly how many years have gone by but my PQ is still probably the most essential piece of my mastering chain. I actually really have no idea what could ever replace it.

Couldn't agree more Sabian
Actually I almost waited 10 years before I could grab one (new) and that must be the best piece of gear I ever bought.
Now I think a switchable "true" shelf filter (with the Q knob on the extreme bands) would be the ultimate "mod" this unit could have. I need to speak with the guys at SPL and see if thats possible to do. The GML 9500 does have this option I believe...Somebody correct me if I'm wrong ?

I was talking about the Spl PasseQ <
But i think im going to go + MP-NV combo for general mixing <
Thanks