Return-Path: X-Spam-DCC: paranoid 1282; Body=2 Fuz1=2 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-0.7 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, RATWARE_GECKO_BUILD autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id u1NAieEA008306 for ; Tue, 23 Feb 2016 11:44:40 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1aYAH0-0007WM-PS for rs_out_1@blacksheep.org; Tue, 23 Feb 2016 10:32:54 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1aYAH0-0007WD-Fu for rsgb_lf_group@blacksheep.org; Tue, 23 Feb 2016 10:32:54 +0000 Received: from smtpout.karoo.kcom.com ([212.50.160.34]) by relay1.thorcom.net with esmtp (Exim 4.86) (envelope-from ) id 1aYAG2-0002xo-Si for rsgb_lf_group@blacksheep.org; Tue, 23 Feb 2016 10:32:53 +0000 X-IronPort-AV: E=Sophos;i="5.22,488,1449532800"; d="scan'208";a="93871085" Received: from unknown (HELO [192.168.1.114]) ([109.176.204.78]) by smtpout.karoo.kcom.com with ESMTP; 23 Feb 2016 10:31:38 +0000 Message-ID: <56CC3509.4040308@lineone.net> Date: Tue, 23 Feb 2016 10:31:37 +0000 From: LineOne User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:31.0) Gecko/20100101 Thunderbird/31.1.2 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: In-Reply-To: X-Scan-Signature: e4383209d2ccb9552700d53c0b540538 Subject: Re: LF: Single Stage Class-B Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-Scanned-By: MIMEDefang 2.56 on 10.1.3.10 Status: O X-Status: X-Keywords: X-UID: 6949 Apart from requiring a higher power supply voltage I find a complementary pair (or pairs) of transistors to be satisfactory and, although the NPN and PNP sets should be reasonably matched to each other, the match between NPN and PNP is not critical. You don't need driver transformers and start with a nice, low output impedance. Hugh, M0DSZ