Just fired up my Zen V2

Shoog · 9th November 2002, 03:45 PM

I have just tested and fired up my Zen amp. For those tuned in about a month ago I found out that the problem with my circuit was that I wired in some salvaged transistors for Q3 and got the lead outs wrong. An expensive mistake.
Anyway sofar the results are quite good. I have no noticable hum (apart from the transformer which buzzes a bit). However I am a little disapointed at the thin bass I am getting. Otherwise the sound is lovely and clean and detailed (tube without the mush). I have a few questions though.
1. I am currently driving it with a passive preamp. This isnt really keeping up. Do you think it might be the source of my thin bass.
2. I am running it at a slightly reduced current of 1.6amps, what effect might this be having on the sound.
3. for Q1 I am using an IRF150 which is cooking nicely, however I am using a IRF240 with an on resistance of 0.18 and its running uncomfortably hot. Do you think a substiution with a IRF150 would bring its temp down.
4.When I fired up I tested the votage at the gate to Q1 and it was at 4V. I have R4 set at max. I have made no further adjustment to this. Would adjusting R4 effect the tonal balance any.

Any pointers as to how I might improve the bass response would be appreciated.
Thanks in anticipation.

Shoog

stefanobilliani · 9th November 2002, 03:54 PM

I have build a Zen and matched it with the Aleph L ,

the bass are deep and loud .

YES for the active preamp!!!

paulb · 9th November 2002, 03:58 PM

Quote:

Originally posted by Shoog
1. I am currently driving it with a passive preamp. This isnt really keeping up. Do you think it might be the source of my thin bass.

I bet if you added the front end as per ZenV4 you could keep the passive preamp.

fcel · 9th November 2002, 04:03 PM

Thin bass is most probably due to inefficient speakers that you are using. I've got good bass from Klipsch speakers but absolutely no bass from Maggie speakers. I have the original Zen amp.

Shoog · 9th November 2002, 04:59 PM

I am using very sensitive vintage Isophon drivers which performed more than well enough with my Leak stereo20 Amp. Look elsewhere for a solution

jh6you · 10th November 2002, 01:11 PM

Shoog

If the bias is 1.6A, R15 of 1k or 1.2k instead of 1.5k might give you a tighter base.

JH

Shoog · 11th November 2002, 05:05 PM

I believe the best approach is to build a Bride of Zen and see what difference that makes. I will hold this sujestion in reserve.
Thank

miguel2 · 12th November 2002, 08:26 AM

I think this thread raises an important question: what voltage and current (power?) is necessary to drive the Zen amp to get its full potential? Of course the speakers will have a big effect on this, but as the gain of pre amplifiers can be adjusted, it would be nice to have some primary figures to point at. I am currently building a ZV4 and I noted in the channel built that I need to increase a bit the gain of my tube pre. But what is the optimum figure?

9th November 2002, 03:45 PM	#1
Shoog diyAudio Member Join Date: Aug 2002 Location: Eire	Just fired up my Zen V2 I have just tested and fired up my Zen amp. For those tuned in about a month ago I found out that the problem with my circuit was that I wired in some salvaged transistors for Q3 and got the lead outs wrong. An expensive mistake. Anyway sofar the results are quite good. I have no noticable hum (apart from the transformer which buzzes a bit). However I am a little disapointed at the thin bass I am getting. Otherwise the sound is lovely and clean and detailed (tube without the mush). I have a few questions though. 1. I am currently driving it with a passive preamp. This isnt really keeping up. Do you think it might be the source of my thin bass. 2. I am running it at a slightly reduced current of 1.6amps, what effect might this be having on the sound. 3. for Q1 I am using an IRF150 which is cooking nicely, however I am using a IRF240 with an on resistance of 0.18 and its running uncomfortably hot. Do you think a substiution with a IRF150 would bring its temp down. 4.When I fired up I tested the votage at the gate to Q1 and it was at 4V. I have R4 set at max. I have made no further adjustment to this. Would adjusting R4 effect the tonal balance any. Any pointers as to how I might improve the bass response would be appreciated. Thanks in anticipation. Shoog

9th November 2002, 04:59 PM	#5
Shoog diyAudio Member Join Date: Aug 2002 Location: Eire	This is definately not the case. I am using very sensitive vintage Isophon drivers which performed more than well enough with my Leak stereo20 Amp. Look elsewhere for a solution

11th November 2002, 05:05 PM	#7
Shoog diyAudio Member Join Date: Aug 2002 Location: Eire	I will try that. I believe the best approach is to build a Bride of Zen and see what difference that makes. I will hold this sujestion in reserve. Thank

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
Fired up DoZ project amplifier	Jean	Solid State	41	18th May 2005 02:14 PM
I just fired mine up.......	reever	Chip Amps	2	2nd May 2005 11:15 PM
Just fired up my CCS'd ECC99 -> SE 2A3	Saurav	Tubes / Valves	14	22nd September 2003 12:40 AM
I finally fired up my Leach Amp!!!!	Kilowatt	Solid State	34	1st August 2002 08:04 PM
Dang... just fired up my first channel of the JLH 20w...	Lisandro_P	Solid State	2	1st March 2002 01:04 AM


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

9th November 2002, 03:54 PM	#2
stefanobilliani diyAudio Member Join Date: Jun 2002 Location: Italy	I have build a Zen and matched it with the Aleph L , the bass are deep and loud . YES for the active preamp!!!

9th November 2002, 04:03 PM	#4
fcel diyAudio Member Join Date: Sep 2001 Location: LA County	Thin bass is most probably due to inefficient speakers that you are using. I've got good bass from Klipsch speakers but absolutely no bass from Maggie speakers. I have the original Zen amp.

10th November 2002, 01:11 PM	#6
jh6you Account Disabled Join Date: Aug 2002 Location: Near to the Pacific Ocean	Shoog If the bias is 1.6A, R15 of 1k or 1.2k instead of 1.5k might give you a tighter base. JH

12th November 2002, 08:26 AM	#8
miguel2 diyAudio Member Join Date: Jun 2002 Location: Portugal	I think this thread raises an important question: what voltage and current (power?) is necessary to drive the Zen amp to get its full potential? Of course the speakers will have a big effect on this, but as the gain of pre amplifiers can be adjusted, it would be nice to have some primary figures to point at. I am currently building a ZV4 and I noted in the channel built that I need to increase a bit the gain of my tube pre. But what is the optimum figure?

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

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