ARC Ref 150 upgrade to KT150 tubes

[Pacha]

I have been enjoying my system since the ARC Ref 2se Phono and Ref 5se Line Stage. A friend mentioned I should consider upgrading the ARC Ref 150 to KT150 tubes from the KT120s it came with.

What is the consensus of the ARC using people here on this upgrade?
Is it just a tube swap or do other components need to be changed?
What would the new bias need to be set at?

I know this will not make it a Ref 150se but, is it significantly better than with the KT120 tubes?

I don't want to go through the expense of the SE upgrade, over $3k, as at some point in the future, within a year to 18 months or so, I'd like to look for a pair of ARC Ref 250 or 250se amps.

Thank you in advance for any comments.

 

[Pacha]

I guess no one has any opinions on this upgrade. I've decided not to persue this and just save for the mono amps I want.
Thank you

 

[Argonaut]

@Pacha....The bottom line being *Yes* the power supply in your REF150, whilst not optimised to run the KT150 like the SE, should have enough headroom to run the larger valve.

Bear in mind that KT150 will draw a little extra heater current from the mains Traffo over the KT120 , the surge current also being greater with the KT150's, in excess of 3 amp initialy, however both the KT120's and KT150's settle down after a couple of seconds drawing around 1.8 Amp/ KT120 and around 2 amp/ KT150 respectively. Bias to 65mA give or take.

If you are US I would recommend Upscale Audio as an excellent alternative to ARC factory KT150’s

 

[Pacha]

Thank you for your advice on the Ref 150 upgrade to KT150. I do think I’m going to wait till I can save enough to go for the Ref 250 amps and maybe even the SE version instead.

 

[Argonaut]

Thank you for your advice on the Ref 150 upgrade to KT150. I do think I’m going to wait till I can save enough to go for the Ref 250 amps and maybe even the SE version instead.

Audio Research Reference 250 SE | Tube

Audio Research Reference 250 SE for sale. Selling a pair of Audio Research Reference 250 SE. Both are in excellent condition, they have been demo pieces that have never left the showroom floor. Original packaging and paper work included as...

www.audiogon.com

 

[Pacha]

Thank you, I’ve been watching them for a bit now. Not sure I have the funds at this time but, I’m working on it.

 

[Pacha]

I'm in conversations with that seller, we will see what can be worked out. I'm hoping to complete this transaction without have to sell my Ref 150 but, time will tell.
Again, thank you for the information.

 

[Argonaut]

Great....Let us know how that plays out

 

[KeithR]

If you order from Upscale be sure you tell them you have an ARC amp and want the cooler biased tubes.

 

[knghifi]

I had REF250 upgraded to SE and changes were all passive parts. Was told majority of SE sonic improvements were the KT150s.

If ordering from Upscale, choose the ARC Select option. This goes for 6h30 and 6550 too.

 

[Pacha]

My friend/dealer talked with David Gordon at ARC yesterday and they are going to see if enough sheet metal/chassis parts exist to build me two brand new Ref 250se amps. Fingers crossed for the last ever pair of 250s with full factory warranty!

 

[Argonaut]

Congratulation....

 

[Pacha]

Latest from Dave Gordon, They have found all the parts necessary to build one more pair of Ref 250se amps. Now I just have to pay for them !

 

[thedudeabides]

Be careful what you ask for, you might get it.

 

[Pacha]

They are on the way!!!

 

[lem321]

Pacha,
Congratulations on the new ARC 250SE amps. I was curious why you decided on the 250SE over the current 160M. I realize there may be a difference in cost. Thank you.

 

[Pacha]

Pacha,
Congratulations on the new ARC 250SE amps. I was curious why you decided on the 250SE over the current 160M. I realize there may be a difference in cost. Thank you.

Actually the list price is about the same around $34k. I'd been saving for over 5 years for the 250s and when they were discontinued I was very disappointed, I looked at the 160s and really wanted more power for the B&W 801D speakers I had and started looking for used 250s. My friend/dealer called ARC and after speaking with Dave Gordon he offered to make one more pair for me and I was able to get a decent discount that would have been hard to match on the 160s. I also like the appearance of the 250s better but, that was only a small consideration. They should be here later this week and my Ref 150 can be put in to back up mode.

 

[lem321]

Actually the list price is about the same around $34k. I'd been saving for over 5 years for the 250s and when they were discontinued I was very disappointed, I looked at the 160s and really wanted more power for the B&W 801D speakers I had and started looking for used 250s. My friend/dealer called ARC and after speaking with Dave Gordon he offered to make one more pair for me and I was able to get a decent discount that would have been hard to match on the 160s. I also like the appearance of the 250s better but, that was only a small consideration. They should be here later this week and my Ref 150 can be put in to back up mode.

Thanks for the back story. I also have the ARC 250SE mono-blocks which I upgraded from the original ARC 250. They're great amps and have been trouble free except for 2 random KT150 tube failures. The first one failed 2 weeks after the upgrade (covered by warranty) and the second one failed 3.5 years later with 1400 hours. The only unfortunate thing is I wanted to match as much as possible the electrical characteristics of the failed tube. As you may know, ARC has their own proprietary system for matching tubes, so the only way to ensure a replacement tube was a good match with the other (7) KT150s was to buy it from ARC. Unfortunately their tubes are on the pricey side (e.g. the KT150 was $275 including shipping), but it provided piece of mind and was worthwhile as the other tubes still had about 1600 hours of life remaining.
I've also considered upgrading the amps to the new and improved ARC 160M but couldn't justify the additional expense at this time. I think you're going to be very happy with your new amps. They provide amazing headroom, extraordinary bass and incredible soundstage, but you already knew that! Congratulations!
Not to put a bug in your ear, but...if you ever get the chance to audition the ARC Ref 6/6SE, you'd be truly amazed!

 

[Pacha]

The new Audio Research Ref 250se amps arrived today. Looking forward to breaking them in!
ARC didn't have any manuals left when they made this pair for me. If anyone has one they no longer need or want I'd be interested.

 

[lem321]

The new Audio Research Ref 250se amps arrived today. Looking forward to breaking them in!
ARC didn't have any manuals left when they made this pair for me. If anyone has one they no longer need or want I'd be interested.

Sorry I don't have a spare one but ARC has a downloadable version online.

Here's the link:

Ref250SE Manual – Audio Research