Audio Research Ref 5 and Krell amps


Just wondering if ARC Ref 5 preamp will mate well with Krell FPB 450 MCX monoblocks. My speakers are Revel Salon 2.
If you ever do this let me know. I've had my eyes on a pair of 450 mcx also.
I will be a great match - the Ref3 was an usual recommendation at the time, as they matched perfectly in electrical terms, and the REF5, that has better definition in the bass and more slam, will be a much better match.
I have no experience with the Salon2 and I am extrapolating from my experience with the REF3 and the FPB750 MCX - I think that the 450 MCX will sound similar.
Sfstereo, I own the REF 5 and used to own the Ref 3. I concur with Micro insofar as saying that the Ref 3 and 5 have similar input/output electrical attributes (e.g. impedance, voltage etc). So, if the Ref 3 works well with the Krell, I expect the Ref 5 would as well.

I have had the Krell 450 mcx for a couple of years now. I think about replacing them with the newer EVO series but I am not sure if they are that much better. In the meantime, I am considering getting a new preamp.
microstrip & bifwynne,

Thanks for your feedback. I have always used ss preamps but after reading all the positive reviews on the ref 5, I thought I give tube preamp a chance. I am looking for a slightly larger soundstage and warmer sound that tube is suppose to provide.
Based on the high input impedance of the Krell, the Ref 5 should work well. I am planning to use balanced outputs.

I will place an order the ref 5 in a couple of weeks.

So what is the preamp your using right now with the 450's? And have you tryed any of the Evo preamps or are you strickly headed in the tube direction for a change?

I am currently using a Pass Labs XP-10. I have always had SS preamps so I want to try tube for a change.
Sfstereo, I used to own an ARC Ref-3. I recently exchanged it for a Ref-5. I love my ARC gear, especially the Ref-3/5. Just for fun, I suggest you try to demo an ARC tube amp from a dealer or friend and match it up with the Ref-5. If you do, get ready for a real treat for the ears. The synergy is magical, which should be no surprise.

Two important caveats. First, I have read that a new Ref-5 has a long break-in-period; maybe 500 hours. So if you're inclined to see what the Ref-5 can do when hooked up to an ARC tube amp, be patient. Same holds true even if you pass on the ARC tube amp/Krell SS amp shootout. Don't judge the Ref until it breaks in.

FWIW, I see that a number of Ref 110 power amps are listed on A'gon. Try and use KT-120 tubes. If you want more power, ARC just released for your listening pleasure the new Ref 150, which replaces the Ref 110.

Second, as always, if you road test an ARC tube amp, be sure it will match well with your speakers.

That's about it. Good Luck!!

Not a dealer and no relationship to ARC. My gear is all ARC tube and I suppose I am prejudiced in favor of ARC.

Thanks for the suggestions. I have also read that it takes 500 hours to break-in the Ref 5. At the rate I use my system, there will be a Ref 10 by the time I reach 500 hours. My normal usage is only about 2-3 hours a week. I guess I will just have to leave it on for a few weeks.

Since this is my first foray into tubes, I may consider a tube amp later on if the tube preamp works out. I don't know a thing about tubes, fortunately, I have a very good friend that can educate me.

Aside from my general preference to buy used gear rather than new for financial reasons, you raise another reason to buy used -- used gears avoids long break-in times. The "used" new Ref-5 that I recently picked up on A'gon had about 1100 hours on it. Just broken-in, yeah!!

As I said in my preceding post, I wouldn't drop any money on a tube amp unless you road tested it first. Having a chat with your friend about tubes amps is a good idea.

As a general matter, pre-amps/line stages and other source tube based inputs (e.g., CDP and phono stage)don't require a lot of care and feeding. The tubes last a long time, except that in ARC gear, the power supply may use a power tube (e.g., 6550C or 5881) which may need to be replaced every 2000 hours. Some of the hybrid gear does not use a power tube in the power supply -- it's solid state.

IME, tube power amps, at least my tube amp, requires a little more attention, e.g., power tube (KT-120, 6550C etc) replacement every 2000 hours and bias adjustment. Some tube amps have automatic bias capabilities - my ARC does not. Of course there's always the occassional pesky bias tube resister that could blow if a tube arcs (i.e., goes bad). Fortunately, there's an ARC authorized service tech who lives near me and makes house calls. Very sweet. Frankly, I enjoy fiddling with my amp. I find it relaxing and interesting.

Well . . . good luck again.

I would love to try tube amps and maybe even vinyl someday when I have more time to enjoy the finer things in audio. I have repaired my friend's tube amp a couple of times so I do know that tube amps do require a bit more care than SS.
Just heard CD8/Ref5/Evo 402 into Franco Serblin's new Ktema speaker at a show. Very nice
I used Krell FPB750MCX and 450MCX with ARC ref3 and also ARC ref5. It is a wonderful combination. The ARC makes the mids very musical and still has enough details. It is also not to bright. The KCT has a little more bottom extention but the ARC preamps sound better in the mids. You can not go wring with this combination. Krell and ARC are a perfect match and a lot of audio friends use this combination.

I use it too, both with an ARC Ref 5 and now 40th AE preamp to my Krell Evo 403, great combination!!!!
Thanks for the great feedbacks. Good to know that the Ref 5 and Krell make a good combination. I have ordered my Ref 5 , hopefully it will arrive in 2-3 weeks.

I am also considering a Shunyata Anaconda CX cord for the Ref 5.
You've made a great choice, don't waste money on a stupid expensive cord that takes electrons to the transformer of the unit. Look at Signal Cable if you think you need another cord.
Shunyata and ARC play well together. That's what I have in my system. Very happy with results.

Please consider Elrod's power cords too.
I have many Shunyatas including Anaconda CX and like them a lot, but found a very good combination in ARC Ref One and Elrod EPS2 Signature.
I've gone the other way before with a Krell preamp into audio research VS series amps and it was an outstanding combo on all music and one of the best I have had for hard rock music.
I just purchased a ARC LS26 to run with my FPB-600 and Aerial 10t's! I am concerned about the low end and am thinking of also getting a pair of JL Audio F113 subs to run in stereo! Will see how it goes when it gets here. Really don't want to lose any of my current bass slam.
Boisehomes, congradulations on the LS26 and best of luck with it. Not quite sure how you intend to load its main outputs, but please check my posts on this issue. In my case, I loaded my Ref 3 main output #1 with my ARC VS-115 and main #2 with my self powered sub. The rest of the story is in my posts. If you "overload" the LS26, you may experience best roll-off as well as other sonic degradations. If you think this is an issue, send me an e mail and I will explain how to solve it.

Thanks Bifwynne. I have not thought about overload! If I have any problems I will send you an email!

Boisehomes, just checked the specs on the LS 26. Seems like most (maybe all) ARC preamps and line stages (including the LS 26) should not have their main outputs loaded with less than 20K Ohms. If you load both output mains, the formula for computing combined impedance is L1 x L2/(L1 + L2). So, e.g., if Main 1 is used for an amp with an input impedance of 300K Ohms and Main 2 is used for a self powered subwoofer with an input impedance of 20K Ohms, the combined impedance would be 18.75K Ohms -- too low.
First thing out of the box, call VPi and review with Mike or Harry you problem and path forward plann to so. If they advised you that combine impedance is too low, thereby putting too heavy a load on the pre, they may give you some practical solutions. In my case, I reached out to To Tutay, who in turn built me a custom impedance buggers.
I got my Christmas gift a few day early. Yes, my ARC REF 5SE had finally arrived. It has only a few hours but it sounds fantastic. It has all the advantages of SS - deep bass, extended highs and very low background noise but it also has great mids/vocals and deep soundstage of tubes.

I have compared it to a borrowed Ayre KXR preamp and to my surprise, I preferred the REF 5. That is saying a lot considering how good the KXR is. The REF 5 will sound even better as it accumulates more hours.
Well Merry Christmas to you Sfstereo! Wait until you have ~650 hours on it, that seems to be where it fully settles in and then the Ref 5 sounds amazing!

The Ref5SE is a Ref 5 with power supply upgrades using parts from the 40th Anniverasy preamp. There are also a few cosmetic changes.
Sfstereo, where can I learn more about the Ref 5 SE. This is the first I heard about it. Is the upgrade done by ARC??
I am very confused about this SE version you are talking about, first off, owning the 40th AE I can tell you that almost no part from the power supply of the 40th AE would or could fit into the single chassis Ref 5 (I just solid mine BTW)

ARC has nothing about this on their site and a goo ogle search reveals nothing, where did you buy this????
I think you have to make an appointment to get it done.

List price is 1k above the non SE model
Kenny, the website shows a Reference Power 250 amp but clicking on it leads you to a totally different product ;)

And there's no mention of the 250 anywhere and that's been in audio shows and also available for sale for a few months now.

There is also no mention of the Phono Reference 2 SE but that's in Absolute Sound website already.

I guess the website just isn't as up to date. I only found out about it from my local dealer who's getting just a few new units in after Christmas and he gave me the option to trade my old 5 for the new 5SE with a top up instead of shipping it back to ARC (that requires appointment and shipping back to US and I live in the Far East).
Here's a link

Dealers are taking orders.

You are correct. There is no way all the parts from 40AE can fit into a single chassis. The SE has similar Teflon caps used in the AE and has an additional board with lots of electrolytic caps.

I have not heard the AE but the SE won't top the AE. I think it just slightly narrows the gap between the ref5 and the AE.
Doggiehowser and Sfstereo, just e mailed a local ARC dealer in Philly land. He confirmed that ARC is indeed releasing a new Ref 5 SE version. The announcement could come out at any time. He did not know whether the legacy Ref- 5 could be upgraded. He said (1) the front changed - round buttons instead of square button, insides -- (2) more muscular power supply -- new verticle mounted board with additional 8-12 power caps; and (3) teflon coupler caps.

The dealer said that he has not heard the new 5 SE yet for himself, but reported that the buzz in dealerland is get ready for something special.

Does anyone know if the legacy 5s can be factory upgraded? I don't care about the cosmetic changes to the front panel and round button part, just the guts.
I think there is a big demand for the parts so ARC is probably juggling demand for new orders vs factory refits (which probably includes the buttons and from face plate).

Best to book your order in.

In my case, my dealer just made too hard an offer to resist swapping for a new unit ;)
I received the ref phono 2 SE 3 weeks ago and my Ref 5 SE shows up on Tuesday. When I ordered both about 6 weeks dealer called me back and said the SE was available...but not officially announced. Seemed like a no brainer.

I also have Ayre KX-R...

The Ayre is paired with Sasha's and Ref 250s...the Phono 2 SE/SME 20/3 is one of the sources in that system along with Naim HDX/ARC DAC8. The Ref5 SE will replace Ref 2 in my cabin...paired with Ref150/Duettes...looking forward to putting in system. ARC has really hit it out of the park this year.
My understanding is upgrades will very likely be available...but no official word on price or availability
~13k as compared to ~12k for non-SE version

If the difference in Ref5 SE version is anything like what I am hearing from the Ref phono2's the best 1k I've spent.
~13k as compared to ~12k for non-SE version

If the difference in Ref5 SE version is anything like what I am hearing from the Ref phono2's the best 1k I've spent.
That seems pretty fair, I like that they use the 40th AE faceplate on the SE model (I always disliked the recessed button)

Also makes me glad I just recently sold me Ref 5 before the SE version came out!!!
The loss from selling the Ref5 may be larger than just topping up for the upgrade, no?

Obviously I wouldn't! I was just curious what the price difference was and glad I sold my Ref 5 before the SE upgrade came out! I doubt I will ever need another preamp with the 40th AE, it truly SMOKES the Ref 5 and I loved the Ref 5 when I got it!

I A-B'd them and gave the warm up advantage to the Ref 5 (1,200 hours on it and 4 hours playing time to warm up) v the 40th AE (550 hours and 30 minutes warm up) Their was no comparison, the 40th had EVERYTHING better! Micro and macro dynamics as well as a quieter background and better bass control. The shear speed of the 40th AE over the Ref 5 was unbelievable.
I have access to Ref 40 and just picked up Ref5SE...

When listening to 40 v 5(non SE). I would say the 5 got about 80-85% of the 40...but was weaker primarily in lower register definition and transparency...the 40 just has very little signature. I expect the SE will change this and get closer to 95-98% of 40 for half the cost.

Need my SE to break in but will report in a few months...I don't expect the SE to top 40 but it will be a hifi bargain

FWIW...I think Ref 150 is hifi amp bargain...I have both 150 and 250s...and while 250 is better primarily in low end articulation and at higher volumes...there is a range in which the 150 is almost there for a lot less...and that's a lot of extra $$$$ for music