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Post by puffin on Jan 11, 2023 19:24:30 GMT
Hi Dan. Good to see you on here. Rob.
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Post by puffin on May 23, 2022 6:08:12 GMT
I don't know about anyone else but I find I do my best remembering if I wake up at about 6am or often earlier. Mind you I have to carefully filter out all the rubbish that seems to invade the brain at these times. What I remembered today was that the ACA was designed to be a cheap and simple way for anyone to sample a Class A amplifier. Nelson Pass felt that SMPS PSs had improved so much over the years and were fairly cheap in the 19v or 24v power output that these were recommended for this application.
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Post by puffin on May 22, 2022 16:19:20 GMT
Dual toroids, dual regulated power supplies, by the looks of it. Where did you get the circuit boards from? Does it get appreciably warm when running? It is in fact an unregulated supply giving out roughly 25/26vdc. The ACA can be run at 19vdc or 24vdc with an additional resistor added to the board. The IRFP240 Fets can take up to 200vdc so as long as the other components could take a higher voltage you can go higher. I know there is one builder who runs his at 48vdc. Given that Nelson Pass suggests 19 or 24vdc, then I would assume that he has found that these give the sound signature that he designed for. The amp gives around 8 - 10 watts dependant on the additional circuit tweak and 10 very fine watts they are IMO. You can tailor the sound to a degree by tweaking the gain with a variable resistor. The reccomended setting is roughtly half the full vdc, but some like it lower and some higher. I was gifted the boards and components by a mate a few years ago and thought that I had better get them built.
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Post by puffin on May 22, 2022 15:14:50 GMT
Sorry for the delay. I had intended to take some less fuzzy ones, but have been sidetracked by replacing a large portion of a boundary fence whilst the weather is good. Anyway here they are. The Cambridge Pre below is just for adjusting a Sub volume when used.
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Post by puffin on May 20, 2022 7:47:03 GMT
Anyone here got one of these or heard one? I have just built one and for such a simple circuit and small parts count it is a really great sounding amp. !0w of Class A and you can tailor the sound with biasing the MosFets. Mind you I had some monster heat sinks and a nice case bought years ago when these things were just about affordable.
If anyone is intersted I can post a few pics.
Rob.
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Post by puffin on Apr 13, 2022 8:08:50 GMT
I would like to learn more about electronics and amplifiers in particular. I am not starting at zero as I can already solder and have some of the kit: multimeter, oscilloscope, wave generator. I was given a basic Oscilloscope years ago as a birthday present and have always intended to learn how to use it. I have a basic knowledge of circuits and have built stuff P2P from ciruit diagrams in Elektor and other sources online. I have been mostly succesful building and upgrading stuff and fixing some that had problems, but it would be nice to fault find seeing what others post of their wave forms on sites like Diyaudio. I must dig it out!
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Post by puffin on Apr 6, 2022 8:32:09 GMT
I had already bought the Zen V2 when I made the OP and was running it in. I am very impressed with it for £135. I bought a 4.4mm 5 pole plug to wire up and listen to the balanced output. Both single ended and balanced sound excellent. You get more volume with the balanced out and they recommend you add a power supply. I have lots of low noise adjustable DIY PSs and have adjusted one for 5v and am using this.
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Post by puffin on Apr 6, 2022 8:25:04 GMT
I was wondering recently if if you could get a digital signal from a phone and did an awful lot of reading and it seemed that if I got an OTG (On The Go) cable the G5 had the ability to stream a digital signal through a USB cable. I paid the princely sum of £2.20 so that if it didn't work I wouldn't lose a fortune. Bingo! Spotify straight from the phone to any Dac with a suitable input. I have recently bought an ifi Zen Dac V2 and am using this at the moment with very good results. I also have an old Dacmagic with USB input and it works with this as well.
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Post by puffin on Apr 2, 2022 13:12:33 GMT
Is anybody using one of these? If so what do you think of it?
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Post by puffin on Feb 21, 2022 10:03:47 GMT
Aah, interesting. I use a wireless mouse, but wired keyboard. Bit spooky in that I was clearing up the study this morning tha I use as a tinkering station/workshop for all things audio and found a wired mouse that I assumed had been lost for eternity. Will give that a go. I have also seen a YT vid about rolling back/and/or updating the audio driver as well as tweaking the start-up settings.
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Post by puffin on Feb 20, 2022 12:10:30 GMT
I used to use Fidelizer when I had a pc based system. Along with a whole bunch of free software (BugHead etc). I did not get any issues with it but would say on reflection marginal gains with Fidelizer. (this is over 5 years ago) No idea what is causing the issue, but maybe you might not be able to use it Hi John, Yes, the difference is marginal with the settings set at the levels set at install, but I have played with a few of 20 frequency boosts and cuts and they are pretty subltle and need further playing with. The noise is not there all the time and today I found that if I opened the browser it made the noise more than I have previously heard. There are suggestions online about changing the settings of which programs/apps are automatically opened on start-up. I will look into that.
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Post by puffin on Feb 20, 2022 12:05:09 GMT
I used to use Fidelizer when I had a pc based system. Along with a whole bunch of free software (BugHead etc). I did not get any issues with it but would say on reflection marginal gains with Fidelizer. (this is over 5 years ago) No idea what is causing the issue, but maybe you might not be able to use it Hi nmartin, It's quite a clever thing in that you can switch it in and out on the fly. When it is out oif circuit I have no noise at all.
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Post by puffin on Feb 20, 2022 10:20:26 GMT
I have just downloaded this on my PC to use in conjunction with Spotify. I can stream in one of two ways, USB out to Dacmagic or USB to digital board and then Dig cable to DAC.
With both of these options I get occasional noise which sounds like "static" in short pips of 2 or 3 or more on occasion. Sometimes music will play without this interference. It sounds to me like it may be a sort of signal overload, but reducing the level of Spotify does not make any difference.
Has anyone had this?
There are several suggestions form Googling that I could try e.g Update Driver but I wondered if any one else has had this before I start messing about.
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Post by puffin on Jan 6, 2022 8:30:35 GMT
From Seal - Seal album. Some/Many of you may know this track. When I first heard it I was struck by how clever and complex it was and not something I would have associated with Seal. It could have come from a film soundtrack with a soundscape washing around behind Seal's sparse vocals and old film clip snippets dotted around for flavour. Another epic Trevor Horn masterpiece IMO.
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Post by puffin on Dec 9, 2021 13:25:49 GMT
Anyone here use a Pre with Light Dependant Resistors? I built one about 10 years ago from the details on Diyaudio posted by the designer of the Lightspeed Attenuator. It has never left my system and is still gooing strong all these years later. My impressions of the SQ is that for a passive attenuator it sounds nothing like any other passive I have used. Detail retrieval, depth and timbre are IMO excellent. I also find that there is an airiness which other passives lack.
I did pay a lot of attention to the PS by using some Teddy Pardo DIY Power Regs and a JLH Ripple eater.
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Post by puffin on Dec 9, 2021 8:17:13 GMT
I have just been given a good quality PC by my son. In the past I was "Streaming" through a Chromecast to good effect. The audio was sent to the CC by bluetooth from an Android tablet using BubblePNP and probably other electrickery that someone else set up for me. Things went a bit wrong and as I hadn't set it up I stopped using the CC
Some years ago Elektor mag showed you how to convert an external sound card that you see on ebay for a few pounds to a DIY USB to SPDIF board. SQ is excellent by the way....well it is to my ancient ears.
I am now listening to Spotify direct from the PC through the USB/SPDIF doodah. Have I now entered the 21stC by streaming my music (again) or does this term only apply to wireless transmission which is how I was using the CC?
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Post by puffin on Feb 25, 2021 17:32:30 GMT
Thanks. The enclosure was mega expensive. Bought years ago from "The Works" (probably intended as a trinket or paint brush box) £7 Some judicious cutting and a few coats of clear wax later........it became an amplifier case:)
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Post by puffin on Feb 25, 2021 13:44:34 GMT
Way back in 2005 one of the members of Diyaudio one Mauro Penasa decided to create what he called an "audiophile" circuit for the LM3886 gainclone. Some of you may be aware of an outfit called Twisted Pear Audio run by Russ White who designed stuff including Preamps and Dacs (Buffalo Dac). Russ White took on the business of making the PCB's for Mauro's design and I think added some expertise of his own. These boards were the subject of a group buy and I purchased two boards to see how different Mauro's interpretation was to the minimalist circuit first seen in the 47Labs Gaincard amplifier. Fast Forward to 2020 and our enforced lockdown. As a way of relieving the boredom I got to work sourcing all the components and getting it done. With half a million DIY amps I can bung into the system at any one time it needed some perseverance. Why can't you get all the bits you require from one supplier! RS had most of what I needed but other bits were much trickier. I built up a massive stash of components about 10 years ago and I am glad I did as the prices have gone up markedly and the stuff stocked is nowhere near as comprehensive. Anyway here are some pics of the finished article. It only has a few hours on it so the jury is out on the subject of SQ and to compare to a standard gainclone.
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Post by puffin on Feb 11, 2021 13:54:25 GMT
I forgot that I had posted about this until I saw it in my posting history. There is a update in that I am not using the ground rod anymore. As I said originally it was being used for signal grounding only. However I wanted to see what it would do if it did come into contact with PE. It tripped the consumer unit! So erring on the side of caution it is no longer attached to any kit.
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Post by puffin on Feb 11, 2021 8:56:58 GMT
I have tried many ClassD amplifier boards over the last 20 years or so. Some I have modded to death following the threads on Diyaudio. The first one I bought and the one that brought ClassD to the attention of the "Audiophile" community was the Sonic Impact cheapo plastic cased portable piece of "junk". Those with much better knowledge ripped the thing apart and found it used a Tripath 2024 chipset which they then modified to be used as a proper amplifier. The 2024 was said to have a 15w output, however in reality the power available without 10% distortion was around 5w. Now you would think that such puny power could not be of any use in the real world (valve amps excepted)....not so, these little things were a revelation and produced a sound that probably matched or in some cases bettered commercial amplifieres from the previous 20 years or so. How did they get such a sound from a chip the size of a postage stamp which was stone cold after a lengthy listening session? Googling will tell you if you don't already know how these things work. Fast forward to the present and there are now many iterations of ClassD architecture. I won't bore you with all the one's that I have or have tried. At the moment I enjoying a dual mono ClassD amp made with 2 mono IRS2092 boards. These boards were recommended on Diyaudio for their sound per £ value and they don't require any modding. They will take a balanced input and depending on the power supply are said to hit a max of 200w into 4 ohms (50v power supply) How much are these boards? I got mine for around £10 each, they are now much much more expensive...£15 - 20 depending on where you buy. If you can put together a simple Lego kit then you can make an amplifer. You don't need to populate the pcb's, just add a power supply...linear or SMPS as long as they will do at least 5A output, some RCA's or XLR's and speaker binding posts, IEC inlet etc etc and present it all attached to your finest piece of scrap plywood to make sure that it all works and that it works for you as an amp before making it look pretty.
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