Note: SE sounds fairly different from balanced/bridged.
Look forward to your impressions.
dave
Look forward to your impressions.
dave
We'll see! It got quite late so after the unboxing, running over the BOM and parts and some rambling about personal techniques and someone from around here joining in too (!) I ended up getting the resistors on the first board mounted and then sent people over to a friend with a raid.
It's nice to know my knowledge is good enough that while trying to check the board for any misplaced components I can kind of spot stuff being wrong just by knowing what can and can't be right. I never thought I'd rack up this much intuitive electronics knowledge but I still did!
It's nice to know my knowledge is good enough that while trying to check the board for any misplaced components I can kind of spot stuff being wrong just by knowing what can and can't be right. I never thought I'd rack up this much intuitive electronics knowledge but I still did!
So...I wanted to hear the ACA's in balanced mode so much that I went out and bought a PL XP-10 😀 The combination is lovely and I've been spinning a LOT of vinyl over the last couple days. Now I have to cycle back through all the different ACA modes with this pre to figure out what I'm hearing...
Well, i'm very happy with it, running it in stereo now with my CHN110 MLTL's. Volume is limited of course (but loud enough for my room on normal listening levels). The sound is close to the Prima Luna tube amp i have, but less soft, more edgy transistor sound, but with the harmonics i love. I heared quiet a few class A amps (Sugden A21, Pass Labs XA and XS, Musical Fidelity A1, ...) before that cost way to much money for me, but this one is not worse I have the impression (just lower power than some). For it's price is a steal, and i'm very happy with how my friend HumbleDeer assembled it with a precision and eye for detail i could not do.
A second one is certainly what i will do in the (near) future. But first i got quiet a few other projects that i need to finish now woodprices are dropping again after the covid madness...
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Well, this was a mild success! Kind of. I didn't end up streaming the latter half, but the assembling of the kit and doing the artful electronics was fun and useful. I heard @waxx got a lot of questions about where they can buy this amp. This may be an opportunity to do more of these streams together with some DIYAudio members, if there's interest! I'm surely excited to be building and maybe modifying some of these amplifiers.
As such I'll also be thinking about building a set of boards with some G2R-2 relays (and a small signal one for contact health) that can screw onto one of the case screws. Add a relay & timing circuit that keeps the relays off for X time after power is applied. I could in theory also hook some bi-colour LED's into this to make the front panel LED's change status colour! Though @waxx pulled an eye at the idea of anything that is brighter than no LED 😛
Another thing, too, is that I think I might want to design a wooden case for an ACA and make it masterfully pretty with some home-boiled linseed oil. 🙄 That woodworker history in me never leaves.
I would be interested in collaborating with the ACA community to add better pictures to the ACA 1.8 build guide. Is there somewhere I can (myself) suggest edits to the guides on the DIY site? I know the software used is capable of it - if I got the software guess right. 😛
Volume is limited? I sure damn enjoyed some roots on them.
You know where to ring the bell. Always happy to have some fun making amp porn. We now have some extra plywood, too, to make some nice designs of things and bobs. Not to forget that I have these sheets of 'veneer' (it's actually the packing material they use to ship plywood in) to use tactfully.
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Well, you won't do house parties with this amp and a 89dB sensitive speakers, but for general listening without an active preamp (like i do now with my passive preamp) it's surely loud enough. But 2 in mono will give more headroom and options to use this amp...
There are mods you can do to increase the gain just a bit, if you wish. Or we continue with those preamps. 🙂
Let's do that preamp first, i like it like it is and when i have the second the power doubles which will be enough for me...
The volume is mostly limited by the lackluster output from your DAC; you need to drive it to nearly the full 2v RMS and I don't think it does that.
HumbleDeer & waxx. why don't you guys head over to the H2 thread and ask Carsten to get you some kits? There are still some available for the asking. The H2 + ACA has a wonderful warm sound signature, plus the H2 also has some gain - maybe just what you need for a bit more SPL.
https://www.diyaudio.com/forums/pass-labs/327746-h2-79.html#post6744954
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I would if I could! I just don't know if I have the money to buy more stuff right now - i'm already working on a DSP design (a pcb) that would use the same chips as the MiniDSP 2x4, have the same basic quality, and cost only about €40 for me to make (as a hobby project. 😛 )
These experiments should then lead to @waxx's 2x8 DSP & amplifier - for a project we're working on.
These experiments should then lead to @waxx's 2x8 DSP & amplifier - for a project we're working on.
It could be interesting depending on the price. But as Humbledeer has a lot of parts in stock, it may be she designs something herself. It's still somethnig we need to discuss and study. In any way, i'll get a transistor preamp as my old Luxman C-02 preamp is not doing it good enough anymore, it can't keep up with the quality of the rest of the chain.
In this case it would mean disharmonic distortion, as the transistors have started wearing out their junction after so many years of being on for hours on end. Same for the caps, though that's a known thing. Other components that have worn out from age also cause the amp to lack the power and signal path it needs to maintain what it's designed for; losing bass and highs or them being distorted beyond reasonable limits is kind of common when caps go bad and silicon starts drifting mildly (causing imbalanced current flows.)
Selling it in the current state is more profitable than trying to repair it first. 😛
Selling it in the current state is more profitable than trying to repair it first. 😛
Well, the caps were replaced 5 years ago, but the transistors are indeed the problem i think, that device is build with 1980 parts and has been used until now with the original transistors that became noisy first and now start to distort. The only thing that is not orginal at it are the elco caps. I did not measure it out, but 5 years ago the tech that replaced the caps said that would happen (and he is a luxman expert). But repairing that is indeed expensive as the original transistors are not made anymore and very expensive on the second hand market.
Good luck with that. 😀 The H2 is a Nelson Pass design - you should know who that is because he also designed the ACA.
The H2 is a preamp - just add attenuation. And btw, it's for FREE, i.e. no cost. You may have to pay Carsten some postage from Germany, though.
Keep in mind that I wouldn't have suggested it if I didn't know what the ACA + H2 together sounds like. (hint: look in my signature) 🙂
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