Cary 300SEI...tube rolling for bass, etc.
 

Hi guys,
I have Cary 300SEI only a year old (and factory upgraded) that is sounding great, with the exception of bass quantity. I would like to coax a little more overall bass out of the amp if possible. My tube set is as follows...

Output tubes - Genelex Gold Lion 300B
Input tube - 50's Sylvania Bad Boy 6SN7
Driver tubes - WWII era RCA grey glass VT-231's

I am guessing to improve the bass, I should go with different 300B tubes? Just hoping for opinions here, as the unit is already upgraded from the factory with Clarity Caps, Hexfreds, Kimber Cable, etc.

FYI, my speakers are Tyler Acoustics PD15's, which have a relatively flat 8 ohm impedance and are rated to drop down to 38Hz. I have read a lot of good things about the Genelex 300B tubes...just would like a little more bass out of my system.

The best sounding 6SN7 I've heard in my SLI-80 is the coin-base RCA/GE. They are late production tubes. May or may not help in your 300B amp. How many hours do you have on your Clarity caps? Took ~300hr for mine to finally settle out. Wonderful sounding upgrade.

I will check into those 6SN7's. I don't see those very often. Not too familiar with them. My 300SEI has around 150-200 hours. Sounds like some break in time is in order. Thanks for mentioning that.

I like those VT-231 RCA's myself. You may need a bit more break in.

Rolling tubes will not likely work. The 300SEI is NOT a bass champ. You may want to consider a subwoofer.

My 300SEI is actually starting to sound much better...I have been letting it play for a couple days now. Sitting down to listen tonight and the whole sound spectrum is opening up...wow! Never quite experienced burn-in this dramatic before. I guess the Clarity caps take quite a while to open up.

I have been looking at some of the high-end 300B tubes...Sophia Royal Princess, Elrog, and EML. They are quite the investment, but I am really curious what they do to the sound. It's too bad they cost so much. It would be quite a pricey experiment. Hmmm.

You might talk to the folks at Cary about tubes. They've likely heard most of them.

Great idea. I actually ordered a new pair of EML 300B's to try. Quite an expensive experiment, but I have always wondered about those tubes. They appear to be built very well. I will keep you guys updated.

I've read a lot about the bass response from Ken Rad 6SN7's. I would like to try those tubes at some point as well. I think the black glass ones with staggered plates are the best...but I'm not too sure on that just yet. Still trying to do some research.

Did you purchase it upgraded or have the upgrades done recently? I see you have EML 300B's on the way. They are nice tubes but do check with Cary about using them in the amp as it does run the 300B's pretty hard. A poster on another forum had major problems with the Sophia Princess in his 300SEI. Just curious, have you tried swapping the driver and input tubes? 300B's are generally not bass champs and you may be getting all they can give but you won't get solid state bass. I never thought I was missing bass with any of the 300B amps I had until I found internet audio forums. They were driving Klipsch LaScalas. The main thing is that it sounds good to you.

You have some nice old production 6SN7's. On a lark I tried a pair of Psvane UK 6SN7's and in my amp, one of Dennis' Inspire SEP's, they are outstanding and at $90 a pair delivered are not stupid expensive. I read about them on another forum where they were being used in a Cary SLP 05. :thumbsup: per that poster.

Enjoy your amp! :music:

The old Stereophile review of the CAD-300SEI is a hoot to read. The reviewer was Bob Harley and he had generally superlative things to say about how it sounded.

Examples: "It was unmistakable, however, that the 300SEI communicated the music in a way I'd never experienced before. There were an immediacy and a palpability to the sound that were breathtaking"

"This liquidity and lack of electronic artifact produced a relaxation and intimacy with the music that made me want to play records and CDs long into the night. In fact, I spent night after night totally immersed in the musical experience provided by the 300SEI and the Compositions."

"The 300SEI was a musical revelation, providing a totally involving and musically euphoric experience night after night. The 300SEI excelled in the most important areas: harmonic rightness, total lack of grain, astonishing transparency, lifelike soundstaging, and a palpability that made the instruments and voices seem to exist in the listening room."

But then came John Atkinson and his measurements. Here's some of the things that JA had to say about them:

"Given the fact that Stereophile would not recommend at all a loudspeaker that showed as unflat a response as the Cary when driving our standard simulated load, I don't regard this amplifier as a hi-fi product at all. It is actually a tone control, and an unpredictable one at that."

"The 300SEI's crosstalk is shown in fig.5. The amplifier measured a straight 40dB of channel separation across the audioband—mediocre performance at best. This poor measured separation may have been due to noise as the signal/noise ratio was also less than impressive."

And this by Bob Harley:

"I could be kind and use the phrase "less than ideal" to describe the 300SEI's technical performance. But I'll tell it like it is: this amplifier measures so poorly it's a joke."

Cary Audio Design CAD-300SEI integrated amplifier | Stereophile.com