2359glenn | studio
Mar 9, 2014 at 12:05 PM Post #8,972 of 39,994
  What you need is a 300B amp with 40 ohm output like David's Selah

 
I have that on my wish list as well. 
biggrin.gif
 I'd like to build the other amp we talked about first though.
ph34r.gif

 
Mar 9, 2014 at 4:33 PM Post #8,974 of 39,994
  After moving 3.75 miles NE to another residence, even the 2359glenn OTL Silver Hawk decided to move from its prior position inside the rack. Now front and center. 
normal_smile .gif

 

i want this rack!!!
 
Mar 10, 2014 at 2:15 PM Post #8,979 of 39,994
Hi everyone,
 
I received Glenn's OTL amplifier a few weeks ago (see picture below) and I have been enjoying it very much... so much that I didn't have time to write much lately :)
 

 
I posted some preliminary impressions on my blog (tweak-fi), but here is a copy of what I wrote using the ALO recabled Beyer T1s :
 
"Power tubes :
- With the two RCA 6AS7s, the sound is reminiscent of a bigger more complete LD MKIII - it is very appealing, and simple to like
- With the six RCA 6BL7s, the sound was very different : much more refined, more extended in the frequency extremes, more delicate ... but it took me some time to "get it"
 
Driver tubes (6SN7) :
- The sound with the stock 6SN7 RCA Glenn provided with the amp was neutral and dead quiet (no noticeable noise floor with my Beyer T1s)
- The sound with Sylvania 6SN7W was very nice : more refined, richer and warmer than the "stock" RCA. However, the noise floor is higher than the stock one, though once the music is playing, it goes slightly unnoticed
- The sound with the VT231 6SN7 Sylvania was fantastic : great timber, great soundstage and excellent resolution but there is a annoying buzzing on the right channel --> I hope it can disappear with burn-in
 
Rectifier :
- I personally didn't like much the sound of the 3DG4 tube (Westinghouse and Zenith). The sound was very "strong"/powerful but at the expense of the soundstage layering and spaciounsness
- The 5AW4 RCA worked better, especially in the soundstage department
 
I wrote those impressions after listening for only a few hours. I will post some more detailed impressions/review later on.
But the more I have listened to this amp, the more I came to appreciate what Glenn has done. It is a dynamic, fast, accurate and "rich sounding" amplifier. I was fearing that a tube amp might be too warm or not enough detailed, but the resolution of Glenn's amplifier is as good or better than anything I have had the pleasure to listen to."
 
 
Since then, I acquire the HD800s and they worked perfectly with the amplifier.
 
I am wondering about a few things though :
- Can one use six 6SN7s on the amplifier instead of six 6BL7s?
- Would the gain of 6SN7s be higher or lower than that of the 6BL7s (in the output stage)?
- Has anyone tried anything than the 3DG4/5AW4s as rectifiers for Glenn OTL amps?
- I looked around for "modern" 6SN7s to try - and I came across the Sophia ones. Did any one try that brand? Is it really low noise?
 
I will write a detailed review of Glenn's amplifier in the coming weeks as I get a better hold/understanding on the sound with both the Beyer T1s and HD800s. 
 
Happy tunes everyone!
 
Mar 10, 2014 at 2:32 PM Post #8,981 of 39,994
Thanks for sharing, slim.a, nice contribution and photograph. What is the function of the silver disc up front, a cover or dial perhaps?
 

Users who are viewing this thread

Back
Top