Two Channel System Changes - I've Been Krelled!

SCompRacer

Other than DAC's and turntables, my system has been pretty stable since 2006. Same pre amp, amps and speakers. I was very happy with it all, particularly the ModWright phono stage built into the SWLP 9.0 pre amp, but wanted to improve digital playback. So I built a dual mono Twisted Pear Buffalo III DAC that was designed for balanced output. I achieved, even surpassed, my goal. More about the DAC later.

My active crossover/amps have balanced in so I needed a balanced pre amp. Single ended sounded fine, but connecting the DAC via balanced direct to my amps gave me some improvement I did not want to lose. It wasn't just the increased gain as I use a dB meter to compare music at the same sound level. I wanted a balanced pre that wouldn't get in the way. I could stay DAC-active but need a pre because I am not giving up my turntable.

Ed Savinon and Carl have been trying to get me into Krell gear for some time, so I bought a 23 year old Krell KSL pre amp from Ed. It included a KSL phono card. After a total recap and tune up I tried it out. I had read reviews of the Krell KSL. I probably shouldn't have as it gave me some negative thoughts about it. Well I was wrong. It sounds wonderful and will remain in the system. Even the phono stage sounds great. I had Jay over to hear if I was right or wrong.

My DAC is kind of a Swiss knife; I can export and play I2S (CD) and DSD (SACD) through my DAC from a modded Denon 3910. Great for music meets when folks bring hard media. I can do hard drive based flac via SPDIF coax in. I can also do USB to I2S and native DSD via USB. I2S separates the clock from data where the clock is embedded in the SPDIF signal. Even though my DAC handles SPDIF in a way that does not rely entirely on the clock, well implemented I2S improves the sound quality. Shunting power supplies are used along with dual discrete output stages. Incredible detail, smooth, no harshness, no glare, no bleeding ears. Absolutely the best digital I have heard in my life.

I used a pic Carl took of the pre as I can't seem to take a good one with the flash. Things are kind of a mess as I had not decided until today what to keep. This pre used to belong to Carl's friend, Dipole Dan.

schwarcw

Great looking set up Rich! No pizza boxes? LOL!

The Krell board looks great! I am so glad to that it sounds splendid after a recap!! I have the Krell KSA-250 in the house. If I could only lift it!! LOL!

Man that DAC has me spurting wood!!

Great job!

leroyjr1

Nice looking setup you got there. I bet it sounds great.

schwarcw

leroyjr1 wrote: »

Nice looking setup you got there. I bet it sounds great.

Leroy, his system sounds amazing. I haven't heard the DAC yet, but just following his build thread is enough to spurt wood.

Loud & Clear

Awesome, Rich. Top shelf hardware combined with very clever system integration. Impressive.

Nhpm510

Curious what you'd think after a couple of weeks of Krell and then putting the MW back in (still better or just different?)

GL

SCompRacer

Thanks for the kind words! Carl, 10 years ago I might have picked that amp up myself but not now!:eek:

Nhpm510 wrote: »

Curious what you'd think after a couple of weeks of Krell and then putting the MW back in (still better or just different?)

GL

No argument there, I've often said sometimes we chase different and call it better and am sure I am on record here saying that. The total system combination is also a factor; what works for me in my system may not work for you in your system.

The last few weeks I have already gone back and forth between the pre's and early on preferred the Krell for digital playback using balanced in/out. The ModWright of course is just single ended out. Initially there was a left channel noise and gain issue with the Krell phono board when set to MC so I preferred the ModWright for vinyl.

I'm not a balanced fanatic and always believed it depends on the gear and design. Twisted Pear offers two I/V or output boards for their Buffalo III DAC. If you look at the Legato output boards used in my DAC, you will see the greatest effort was placed on balanced out with this I/V stage. Balanced out is a discrete design, has less components in the signal path and offers common mode noise cancellation to the inputs of the next stage. Single Ended out requires conversion. Not to say SE sounds bad, but balanced out sounds slightly better in my system.

A built in phono stage is not essential to me, and I had considering keeping the Krell and adding an external phono stage, either DIY or commercially manufactured. But the KSL phono board design, despite being a high parts count, looked worthy of repair to experience it (although not at $125 an hour for Krell to do it). Once I got the MC phono board issue resolved, I was happy to find it sounded very good too. (Once upon a time internal phono boards were more than just something to stick in there in case you needed one).

I have the greatest respect for Dan's gear. The ModWright SWLP 9.0 is a high current, extremely low distortion tube design. It has a low noise floor and is very punchy and dynamic. I feel the Krell has an even lower noise floor, offers more nuanced dynamics and frequency extension without color. It does this with no brightness or fatigue. However some might still prefer the ModWright sound and I'd be OK with that.

One of my friends (Jay) was here and in post 16 in my DIY/Mod thread he shared what he thought about it.

http://www.polkaudio.com/forums/showthread.php?142724-Krell-KSL-Pre-Amp-Phono-Board-Recap

ESavinon

Welcome to the darkside! The conversion has been completed! Let me hear you say KRELL,KRELL,KRELL!

Toolfan66

leroyjr1 wrote: »

Nice looking setup you got there. I bet it sounds great.

Agreed!! Audio wood!!

zingo

Behold the power of the Krell!

Congrats on the new preamp by the way; great unit.

SCompRacer

Thanks for the kind words and images!

ESavinon wrote: »

Welcome to the darkside! The conversion has been completed! Let me hear you say KRELL,KRELL,KRELL!

KRELL,KRELL,KRELL! I've been assimilated to the Krell by the Savinon....:cheesygrin:

nspindel

http://www.polkaudio.com/forums/showthread.php?84227

wayne3burk

http://www.audioasylumtrader.com/ca/listing/Speakers-Planar/Sanders/ESL-10B/Electrostatic-Speakers/34968

I was wondering what them there speakers were.... I bet they sound belly belly nice indeed.

SCompRacer

nspindel wrote: »

http://www.polkaudio.com/forums/showthread.php?84227

Kewl! The KAV-2250 is a great amp!


Weather and schedules permitting, I may be meeting with Carl soon to reunite the KSL with it's old friend, the KSA-250. It also belonged to Carl's friend, Dipole Dan. I'll have to pull more wires for another 20 amp circuit just to try it out.

SCompRacer

wayne3burk wrote: »

http://www.audioasylumtrader.com/ca/listing/Speakers-Planar/Sanders/ESL-10B/Electrostatic-Speakers/34968

I was wondering what them there speakers were.... I bet they sound belly belly nice indeed.

Thanks, I sure like them.

Mine are actually InnerSound Eros MK III's, but do have the durable Ultrastat panels used on Sanders 10b's. Roger has claimed he has never had an Ultrastat panel failure. The MK III's were also supplied with the remote control 600WPC @ 4 Ohm MK II active crossover bass amp. Used MK III's also sell for quite a bit less. MK II panels will have the powder coated metal stators. One other detail is SEAS no longer makes the same long excursion woofer used in my speakers. The new ones reach a bit deeper but the older ones go a bit higher and integrate a bit better with the panels.

thsmith

Very nice setup.

You could use a Harmony 1 remote though ;-)

SCompRacer

thsmith wrote: »

Very nice setup.

You could use a Harmony 1 remote though ;-)

Thanks!

10-4 on the Harmony! The remote for my active crossover bass amp is programmable. I had my ModWright Sony 9100ES player and ModWright pre amp volume in it. Now with the remote DAC a Harmony looks like a better and easier fit. Along with source, display and digital volume, I have complete I2C control of the DAC chip including PLL lock and Quantization settings for fine tuning of all the supported sample rates (44.1Khz to 6.144 Mhz).
.

george daniel

Looks like you've got it "dialed in",,way to go fellas'

george daniel

Looks like you've got it "dialed in",,way to go fellas'

wolfsongaudio

How does the DSD get output from the modded 3910? I have been looking for a solution to allow DSD out of a transport into a NAD D-51 and have not found any transports that can send DSD or even a working 96 Khz "Downsample".

wolfsongaudio

Also, be sure to re-cap that KSA 250. Krell gets almost 2 kilo dollars plus shipping two way!

SCompRacer

wolfsongaudio wrote: »

How does the DSD get output from the modded 3910? I have been looking for a solution to allow DSD out of a transport into a NAD D-51 and have not found any transports that can send DSD or even a working 96 Khz "Downsample".

You have to snag the signal off the board from the transport before the DAC chip in the player. You can do this with any player that you can ID the DAC chip and download the data sheet on. Some DAC chips have separate circuits for I2S and DSD, some share circuits like the PCM1796 in the 3910. On this DAC chip, the sharing ends up with a R and L channel swap in DSD that must be addressed due to my DAC chip input connections. I used a Twisted Pear OTTO II digital switch that corrects the channels and is controlled by a mechanical switch on the back of the player. Once activated it exports a proper channel phase; off I'm good to export CD.

Now the I2S bus was designed for in chassis, primarily on board communication separating clock and data for the lowest jitter. Wiring must be kept short and exact length, like 4" max per the smart folks (although some DIY folks break that rule on wire length). If you use a long cable, you can lose the benefits of the separate clock/data lines I2S/DSD provides. LVDS (Low Voltage Differential Signaling) is the best way to move the I2S/DSD signals from player to DAC. One set up for send, one for receive in the DAC. We are dealing with digital so no harm comes to the SQ. The Teleporter also provides isolation.

I built a DAC that already had inputs and devices for I2S/DSD input. Twisted Pear offers a LVDS Teleporter and OTTO II digital switch that made this mod easier. The Teleporter allows for up to 100 feet of Cat5/Cat6 cable to be used. Working with an existing design that has no existing inputs/outputs is one of them 'void your warranty' and if it doesn't work and you can't figure it out, all you have is the DIY community to help. (And I've had some help!). I even added I2S out of my SB Touch using a Teleporter to transmit.[/QUOTE]

SCompRacer

wolfsongaudio wrote: »

Also, be sure to re-cap that KSA 250. Krell gets almost 2 kilo dollars plus shipping two way!

10-4 on the recap. I've done some research on it.

schwarcw

Amazing research and savy to intercept the signal in the DSD domain. Nice work as always!

tonyb

Congrats on the Krell Rich. I used to dig their older gear, build like a tank and badass no doubt. You don't hear their name much anymore. Used to be, people described them as being sterile sounding. Never found that to be true with their older stuff. Dedicated lines to run their gear however is a must to get the best out of them.

Wouldn't mind snagging one of their integrateds either, like the 300. One look inside is all you need to see why they hardly ever come up for sale on the used markets. Try finding that build quality today. Have fun tinkering Rich, don't know where you get the time, but all of us are glad you do.:biggrin:

SCompRacer

Thanks Carl, Tony.

A smart fellow told me the KSL parts count is high for a balanced discrete design, but without a schematic he can't pass judgement. Some folks prefer the newer Krell pre's, saying they just got better. The phono boards changed slightly but remained similar in design. My ESL's are revealing but they seem to be kinder to some gear than other speakers. One good thing is my total system dollar investment is going down but enjoyment is increasing. I like that formula.:surprised:

All I gotta do here is keep the wife and cat happy and I can do what I want, within reason and no stray kittys.:twisted::cheesygrin: I think of all the time and energy spent on audio gear and I had really neglected digital. I still don't understand everything fully...but do understand it much better. While having the higher sample rate capabilty is nice, there isn't that much available or it's too pricey to pursue (like DSD). While the software exists to increase bit rate, it doesn't add more detail in the data...but does move quantization noise out of the audio band. The DAC chip also employs different filters for the higher bitrate material. If it is better or not, that is up to the ears of the beholder.

I'll put something together in the next month or so and send you an invite. The RAS crowd hasn't hooked up in a long time.