HELP - SMART 845 or 300B SE

neobartom · 15th June 2011, 05:23 PM

Hello All,

I have a monoblocks Unison Research SMART 845 and 2 weeks ago I had here a stereo 300B amplifier " My new 300B Amp " - And my lovely SMART 845 desapear , the 300B was much better in all.
Since than I didn't sleep well thinking about that.
My question is : I try to sell my 845 and look for a good project and buy good elements and build a 300B SE monoblocks or stereo, or open my SMART 845 and change the cables the power supplies ,resistors etc,etc? what is the best .
I know and I'm a little afraid that 845 can kill me, lethal, I´m newbie ,but before the project I need to buy all and it will be with time and I will learn and I have a friend that is very good in electronics he works with ASR/PAR radares (technician).

thanks in advance for yours replies.

Neobartom

azazello · 16th June 2011, 02:56 PM

1. 845 is good, but not the best tube /I like 2A3 - RCA and 300B JJ!/.
2. 1000 v. kikes only one time....no more times!....

the_manta · 16th June 2011, 03:19 PM

First question is rather why you like that 300B amp more than your 845 amp.
Either the 300b amp produces more "triodish" sound because of 2. harmonics (no feedback for example) or your 845 amp is badly made (low quality transformers, no clever circuit design etc.)

The ideal starting point would be now when we would have frequency response, distortion spectrum and circuits of both amps :-)

neobartom · 16th June 2011, 04:01 PM

I can put here the schematic of the UR smart 845 . It's cheaper change some resistors and wires in smart instead build one 300B . My smart 845 have a good image, focus, but have problems with a lot of information like orchestra, and have 14 dB NFB.

15th June 2011, 05:23 PM	#1
neobartom diyAudio Member Join Date: Mar 2010	HELP - SMART 845 or 300B SE Hello All, I have a monoblocks Unison Research SMART 845 and 2 weeks ago I had here a stereo 300B amplifier " My new 300B Amp " - And my lovely SMART 845 desapear , the 300B was much better in all. Since than I didn't sleep well thinking about that. My question is : I try to sell my 845 and look for a good project and buy good elements and build a 300B SE monoblocks or stereo, or open my SMART 845 and change the cables the power supplies ,resistors etc,etc? what is the best . I know and I'm a little afraid that 845 can kill me, lethal, I´m newbie ,but before the project I need to buy all and it will be with time and I will learn and I have a friend that is very good in electronics he works with ASR/PAR radares (technician). thanks in advance for yours replies. Neobartom

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Unison Research Smart 845 schematics	Zoran	Tubes / Valves	38	10th May 2011 12:42 PM
300B driving 845	otto88	Tubes / Valves	4	7th June 2009 07:47 AM
driving 845 push-pull with a signal from a 300B SE stage	Antonio Tucci	Tubes / Valves	1	20th February 2007 08:04 PM
300B like 845	rick57	Tubes / Valves	24	19th September 2005 10:33 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read

16th June 2011, 02:56 PM	#2
azazello diyAudio Member Join Date: Aug 2008 Location: Bulgaria	1. 845 is good, but not the best tube /I like 2A3 - RCA and 300B JJ!/. 2. 1000 v. kikes only one time....no more times!....

16th June 2011, 03:19 PM	#3
the_manta diyAudio Member Join Date: Nov 2006 Location: Munich, Bavaria	First question is rather why you like that 300B amp more than your 845 amp. Either the 300b amp produces more "triodish" sound because of 2. harmonics (no feedback for example) or your 845 amp is badly made (low quality transformers, no clever circuit design etc.) The ideal starting point would be now when we would have frequency response, distortion spectrum and circuits of both amps :-)

16th June 2011, 04:01 PM	#4
neobartom diyAudio Member Join Date: Mar 2010	I can put here the schematic of the UR smart 845 . It's cheaper change some resistors and wires in smart instead build one 300B . My smart 845 have a good image, focus, but have problems with a lot of information like orchestra, and have 14 dB NFB.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)