Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, RCVD_IN_DNSWL_MED,SPF_PASS,T_DKIM_INVALID autolearn=ham autolearn_force=no version=3.4.0 X-Spam-DCC: EATSERVER: mailn 1166; Body=2 Fuz1=2 Fuz2=2 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by lipkowski.org (8.14.4/8.14.4/Debian-8+deb8u1) with ESMTP id v1FE8Xa7000827 for ; Wed, 15 Feb 2017 15:08:34 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1ce0BX-0006u4-Ne for rs_out_1@blacksheep.org; Wed, 15 Feb 2017 14:03:55 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1ce0BX-0006tv-4c for rsgb_lf_group@blacksheep.org; Wed, 15 Feb 2017 14:03:55 +0000 Received: from porthos.netcom.co.uk ([217.72.171.73]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.87) (envelope-from ) id 1ce0BU-0000y3-K9 for rsgb_lf_group@blacksheep.org; Wed, 15 Feb 2017 14:03:54 +0000 X-DKIM-Result: Domain=abelian.org Result=Signature OK DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=abelian.org ; s=default; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: MIME-Version:Date:Message-ID:From:References:To:Subject:Sender:Reply-To:Cc: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=9bFkQv8cySSwEShrCGr88z1ZaYNODjd1gAxbrKzUTqc=; b=OesFnincs+74jpezZrQ4Uecu0m aQvJMiMdeoQ4pdpmaV2DMbDoCuCWbJnq5mrFprujh6vy3xoDTuj3NsvZrTHcpAutfWCc52jRgJTPo qGwqtx4HbnpNsiOCKU1oQQmEz/+i5LMDDeXCjf6zdvAJECWbtfQZck2a6T+pK6GOnQYw=; Received: from i-194-106-52-83.freedom2surf.net ([194.106.52.83]:47587 helo=pn.abelian.org) by porthos.netcom.co.uk with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.88) (envelope-from ) id 1ce0BT-0000us-Ql for rsgb_lf_group@blacksheep.org; Wed, 15 Feb 2017 14:03:51 +0000 Received: from [127.0.0.1] (localhost [127.0.0.1]) by pn.abelian.org (Postfix) with ESMTP id 34C584005A0 for ; Wed, 15 Feb 2017 14:03:51 +0000 (UTC) To: rsgb_lf_group@blacksheep.org References: <58A38C76.9060406@posteo.de> From: Paul Nicholson Message-ID: <5a6be489-1da5-50d8-b5a1-9ada319703c9@abelian.org> Date: Wed, 15 Feb 2017 14:03:51 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: <58A38C76.9060406@posteo.de> X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - porthos.netcom.co.uk X-AntiAbuse: Original Domain - blacksheep.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - abelian.org X-Get-Message-Sender-Via: porthos.netcom.co.uk: authenticated_id: catchall@abelian.org X-Authenticated-Sender: porthos.netcom.co.uk: catchall@abelian.org X-Scan-Signature: 2e2f7cbbe9f38dd7bf3fac4fc012e6fc Subject: Re: LF: Raspberry Pi sound interface that works 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 2.75 Status: RO X-Status: X-Keywords: X-UID: 10596 I realised that the input and output caps couldn't be the cause of the temperature dependence: the signal and reference frequencies are so far from the corner frequency. It looks like the problem is a defect in the ebsynth software. The input and output buffer delays change slightly as the sample rate varies with temperature. The program isn't correcting for the delay changes. Hopefully have that fixed shortly once I figure out a way to correct it without introducing some slowly accumulating numerical error. > 6 synchronous sampled inputs, that's the perfect system > for the tree. Due April, so they say. I hope it doesn't need an RPi 3 because the power budget then has to allow for the unused built-in Bluetooth and WiFi. I wonder if it A/D converts 6 inputs in unison, or does them sequentially. It might do them in stereo pairs. We'll have to wait and see. -- Paul Nicholson --