🎛️ TOPINCN 6J1 Vacuum Electron Tube Valve Preamp Amplifier Board Headphone Amp Parts Preamplifier Musical Fidelity Kit AC12V 0.8A" - "TOPINCN 6J1 Vacuum Electron Tube Valve Preamp Amplifier Board Headphone Amp Parts Preamplifier Kit, Musical Fidelity, AC12V 0.8A Review

Firstly I am an electronics engineer with over 20 years of experience in this field. It was a fun project to introduce my son to electronics. The board has several test points on some of the caps where you can measure the correct voltage and troubleshoot if necessary. Don't forget to solder the vocals and you will love this project.

I assembled it, turned it on and got a sound like a heartbeat. I have Beyerdynamic DT-990 Pro headphones with 250 ohm impedance. My high-end all-in-one audio DAC didn't have the power to drive them properly. They have about 5-8 dB less output than input and are horribly distorted. Is it possible to get a schematic to try and understand what is going on?

It was fun to build but be prepared. No instructions or diagrams are included. Comes in the form of a pack of spare parts. You will need to print out a resistor color code chart so you can identify the resistors. You need to identify the positive lead (anode) of the LEDs (the longer lead is +). You need a 12 volt AC power source. It would be nice if they included a wall mounted transformer. Price unbeatable.

Was fun to build. I've always wanted a tube amp to blend in with the rest of my audio system, so I figured why not try building my own. It took me a few days to put it together, but once I did, I hooked it up to my laptop, to a DAC, to a tube amp, and then to headphones. The volume is low, I can barely hear the sound coming from this thing. The sound I hear is very muffled and distorted. Doesn't listen at all. Maybe I get a broken idk block. I first bought it because the reviews here said it…

Build my kit last year. Finally turned it on last night. Yes, I've been in my basement for over a year. Purchase a 12V AC power supply with this. In the end I cut off the power connector and soldered it to the board. Works great when assembled correctly. Sounds good. It would be much better if they gave directions. The bottom line is that if you build it right, it works and sounds good. I ordered some old GE lamps from Revain for this. Let's see if they sound any better than the cheap Chinese…

I'm quite an electronics novice. There are many good assembly videos online. I used a multimeter to test my components. Everything else you need to know can be found on the board. Everything in my kit was good quality and easy to work with. The power supply that I bought with this unit is very noisy and cuts off the left channel. So it happened that I accidentally bought a similar pre-assembled unit before. The AC adapter that was bundled with the other device works great with this one. I don't

I have everything but I'm afraid to turn it on. Neither positive nor negative can be seen at the current input (peak ground or middle ground). There is nothing on the RCA jacks that identifies input or output. add nothing at all. So if I did something wrong due to my inability to read Mandarin and her inability to identify key information, it could literally explode in my face! I found another seller that came with a case, better capacitors and parts (like the ones shown in this addon) had more

Fun little project, but the fact that it uses AC power and has its own bridge rectifier confuses me. I might be missing something, but it seems to me that it would be a bit cheaper to design the circuit with only DC input. I also had to buy a 12V AC transformer because I didn't have one (unlike the half-dozen old 12V DC adapters I had in stock). And it basically doubled the price to just over $30, so the value proposition is a bit misleading. You may have a 12V power supply lying around. I saw…

First a word: I'm by no means an audio enthusiast. I just bought this kit because it was a cheap circuit with working vacuum tubes. The kit arrived in perfect condition with all the parts needed. The tubes were well lined with a layer of bubble wrap. The building process was pretty easy. All parts are clearly marked on the circuit board with their component values and polarity. Assembly requires no special equipment - just a standard chisel-tipped soldering iron and a couple of wire cutters. I…