Question on OPT - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

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
Reply
 
Thread Tools Search this Thread
Old 26th February 2005, 07:35 AM   #1
MlinarS is offline MlinarS  Canada
diyAudio Member
 
Join Date: Jan 2005
Location: Hong Kong
Default Question on OPT

Hi,
Does any of you guys have any experiance with ISO(new Tango) OPT transformers specificaly XE-20S. How it sounds (bass, mids, highs, etc.)? The price for pair of this equals the price for single piece of Tamura. Is Tamura twice bether than Tango? Or this new Tango is not as good as the old Tango.

Second question: I calculated parameters for 300B output stage as follows:

First: With Va=425V,Ia=80ma andOPT 3K5 my Po=9.9W and output resistance 1.7 Ohm (into 8 Ohm)

Second: With same Va and Ia but OPT 5K0 my Po goes down to 8.1 W and output resistance also goes down to 1.05 Ohm.

All this is understandable but I don't know if this values of OR are to high (I read somewhere that it should be less than 1 ohm).

If I choose one OPT impedance over the other how will this afect the sound and performance of the amp (if at all).

Your input is highly appreciated.

Thank you.
  Reply With Quote
Old 26th February 2005, 11:23 AM   #2
diyAudio Member
 
Brett's Avatar
 
Join Date: Jan 2002
Default Re: Question on OPT

Quote:
Originally posted by MlinarS
Hi,
Does any of you guys have any experiance with ISO(new Tango) OPT transformers specificaly XE-20S. How it sounds (bass, mids, highs, etc.)? The price for pair of this equals the price for single piece of Tamura. Is Tamura twice bether than Tango? Or this new Tango is not as good as the old Tango.
No idea. Never used them.
Quote:
Second question: I calculated parameters for 300B output stage as follows:

First: With Va=425V,Ia=80ma andOPT 3K5 my Po=9.9W and output resistance 1.7 Ohm (into 8 Ohm)

Second: With same Va and Ia but OPT 5K0 my Po goes down to 8.1 W and output resistance also goes down to 1.05 Ohm.
Sounds about right. Depending on the speaker used and it's implementation, a bit of output Z can be your friend.
Quote:
All this is understandable but I don't know if this values of OR are to high (I read somewhere that it should be less than 1 ohm).
A < 1 ohm output Z in a non NFB SE amp is a very rare occurrence.
Quote:
If I choose one OPT impedance over the other how will this afect the sound and performance of the amp (if at all).
The WE 300B datasheet and the other graphs on the site, show the power and 2H and 3H distortions for the output stage vs different loads. As for sonics, depends too much on what other factors are in the system, as well as personal preferences to give some sort of comment.
I'd go 3k5 myself.
  Reply With Quote
Old 26th February 2005, 12:55 PM   #3
MlinarS is offline MlinarS  Canada
diyAudio Member
 
Join Date: Jan 2005
Location: Hong Kong
Default Re: Re: Question on OPT

Thanks Brett for the responce,
Quote:
Originally posted by Brett
[I'd go 3k5 myself. [/B]
I was thinking same, but I was a concerned about output resistance of 1.7 Ohm. Now from your post it seems that it is to be expected for non NFB design.

Thanks,
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
newbie with input tran. question and wiring question imo Solid State 0 18th January 2006 10:10 PM
Capacitor Question /question on cap TunaFish Tubes / Valves 14 12th January 2004 02:23 AM
PS question - tformer question actually breguetphile Chip Amps 2 30th May 2003 01:29 PM
old speaker question, bullet midrange question & link to speaker project wallijonn Multi-Way 10 5th November 2002 06:03 AM


New To Site? Need Help?

All times are GMT. The time now is 07:02 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2