Kenzie Tube Headphone Amplifier

[exdmd]

 

I recently received a base Kenzie headphone amp from Ampsandsound and wanted to share my impressions. Packaging was among the best I have ever seen always a good sign.

Now I do most of my headphone listening through Tidal HiFi and locally stored files. My chain is PC > AudioQuest Diamond USB > Eitr > Blue Jeans S/PDIF > Brooklyn DAC+ > Kenzie > Sennheiser HD800S phones. The HD800S are my reference phones and will be until Sennheiser comes out with something better under $5000. I had been listening through a Vali 2 while waiting for Justin to build my Kenzie, which only took a month including shipping.

The Vali 2 is a good starter amp for the HD800S. If you have never heard a high end tube amp you could be happy with it. It matches well with the HD800S just add a Bifrost Multibit and you are good to go on a budget.

No disrespect to Schiit but I just spent a morning listening switching between the Vali 2 and Kenzie and the Kenzie outclasses the Vali 2 in all respects. Not a surprise.

The first thing I notice is soundstage and imaging. While the Vali 2 soundstage is between the ears and shallow with the Kenzie the soundstage is deep, three dimensional and extends outside my head with good masters. Not all the time mind you but it does happen. I have never had this happen with a phone other than the HD800.

There was an upper treble sibilance with the Vali 2 that is gone with the Kenzie. Midrange is glorious with plenty of air around voices and instruments. I have no problem following complex bass lines.

Treble is accurate and pleasing, and on well recorded rock albums I can follow the drummer as he plays. It is easy to listen deeply into recordings. I have not found anything to fault yet will update if I do. Every component has its warts; takes some time to uncover. With Kenzie you have the choice of the base Kenzie at $1650 or the full on Encore at $2545 with input transformers and upgraded coupling caps. If your budget is under $1800 don't think you are just getting a starter amp. I consider the $1700 I paid a bargain for value received.

Justin is great to work with. Since I only use 300 ohm phones he ordered a transformer with 32/300 taps:

 

 

Yes, the HD800S sound better from the 300 ohm output and not by a small margin. After I was so impressed with the base Kenzie we struck a deal for Justin to build me a set of input transformers in a separate box that would give me sound closer to the Encore. Like I said, he is a good guy to work with.

 

Everyone automatically thinks DNA or Eddie Current for high end amps for HD800 phones but Ampsandsound is gaining fans because they have a great product at a good price and can ship faster than the competition.

[GUTB]

I spoke with the Ampsandsound guys at CAF. I really like their 300B amp, also it has some speaker taps. I think they also had a 2A3 amp too. I wonder if they'll custom wind a transformer for my TH900. I also talked 845s with them -- one of the guys likes 845s, and the other dude seemed afraid of working with voltages that can kill you. If they came out with an 845/211 amp I'd be all over that.

[exdmd]

Never hurts to ask email Justin at [email protected] he is pretty good at responding to emails. The Agartha uses 300B's and is supposed to drive Heresy III speakers fine as well as phones. Would be cool if they made an affordable 211/845 amp.

[exdmd]

The Kenzie doesn't need tubes to be rolled to get great sound quality. The amp is based on the Darling circuit design using 1626 power tubes and there are no alternates there. You can tune the SQ a bit using different brand 12SL7GT input tubes. I have done some experimenting and found for my ears best SQ from NOS gray glass RCA 12SL7GT tubes. That tube works particularly well with HD800S phones. Tubes are inexpensive which is a plus. The 2C52 has also been recommended as one of the best input tubes for the Kenzie but they are hard to find and quality is not consistent. I bought three of them from different sources, they all sounded different and none sounded better than the RCA 12SL7GT.

[mourip]

On 1/25/2018 at 4:47 PM, exdmd said:

The Kenzie doesn't need tubes to be rolled to get great sound quality. The amp is based on the Darling circuit design using 1626 power tubes and there are no alternates there. You can tune the SQ a bit using different brand 12SL7GT input tubes. I have done some experimenting and found for my ears best SQ from NOS gray glass RCA 12SL7GT tubes. That tube works particularly well with HD800S phones. Tubes are inexpensive which is a plus. The 2C52 has also been recommended as one of the best input tubes for the Kenzie but they are hard to find and quality is not consistent. I bought three of them from different sources, they all sounded different and none sounded better than the RCA 12SL7GT.

 

Try a 7F7 with a loctal to 8 pin adapter. You can get both on eBay and they are much cheaper than even 12SL7s. The 7F7 is an early version of the 12SN7 but uses the loctal base.

 

I have a Linear Tube Audio MicroZotl preamp that allows me to use either a 6SN7 or a 12SN7 by changing a jumper. I tried a number of NOS 6SN7s and 12SN7s including Tungsol round plates (TSRP)  and Kenrad VT231s but the equivalent loctal 7N7 sounded the best to me.

[exdmd]

13 hours ago, mourip said:

 

Try a 7F7 with a loctal to 8 pin adapter. You can get both on eBay and they are much cheaper than even 12SL7s. The 7F7 is an early version of the 12SN7 but uses the loctal base.

 

I have a Linear Tube Audio MicroZotl preamp that allows me to use either a 6SN7 or a 12SN7 by changing a jumper. I tried a number of NOS 6SN7s and 12SN7s including Tungsol round plates (TSRP)  and Kenrad VT231s but the equivalent loctal 7N7 sounded the best to me.

 

Never heard of using an 7F7 input tube with a Kenzie. 2C52's were supposed to be the ultimate input tube for the Kenzie but they are very hard to find now and quality is hit and miss. If you don't mind using an adaptor the Siemens ecc801s is supposed to be very good according to Justin at ampsandsound.