DollaTek HIFI amplificador audio OPA2604+AD827 OPAMP 5532 LM337 LM317 Preamp Pre-amplifier Volume Tone Control Board

Surprisingly very nice sounding pre amp for the price.

This preamplier is small with a well designed and built PCB. It was easily installed in a case with a headphones amp and works well.The op-amps are installed in decent turned pin sockets which makes it easy to try different op-amps to see what suits you best. The non-polarised capacitors are Wima and the electrolytics are Nichicon. The 317 and 337 regulators are quieter and more stable than the 7815 / 7915 normally supplied with similar preamps, and the presets allow you vary the supply voltages to suit whatever op-amps you choose to use, and to balance the positive and negative supplies as precisely as you require.Before powering up for the first time, you would be well advised to remove the op-amps and check the supply voltages are correct - adjust them as required using the preset pots.The preamp is good value for money and simple to use.

Ive tried many different preamps as a front end to my Quad 606 power amp driving Quad 2905 speakers and this one is a keeper. The sonic performance with all the tone controls centred is indistinguishable from using the input source (Amazon Echo Dot3 via AUX) directly into the power amplifier. This preamp gives an amplification factor of 1 to 1 so seems completely transparent when all the tone control pots are centred but of course gives plenty of control over the tone settings if required for different types of recordings and music. Acting on advice given, I did immediately upgrade the 2 IC's to OPA2604. Not sure if this was any improvement over the NE5532's supplied but I'm keeping the OPA2604's in.Nice to see top audio grade WIMA capacitors used in all the signal path locations and no doubt this helps the audio quality to be top notch!

Superb sounding Treble, I had one similar not many caps on board and sounded dull in comparison.

Can't go wrong, WIMA caps...it just works and does what it says on the 'tin'.

schöner klang

This is the pre amplifier I build with the Dollatec tone board. The case is a connection box with vintage Panasonic knobs. I'm pleasantly surprised by the cristal clear sound and good bass this little pre amplifier board delivers. Actually I hear lots of new sounds of music I've listened to for a long time. I've given it a seperate transformer in a sealed box. If you like to try to build an audio device yourself, I can recommend this Dollatek! It's not expensive and good quality.

Si sente bene, le regolazioni sono tutte efficaci, abbinato a un t-amp perché le casse ivi collegate peccavano nelle frequenze più alte questo preamplificatore con regolazione dei toni mi ha evitato di venderle. PerfettoAggiornamento 10/05/2023: il preamp dopo tanti ascolti più attenti sembra fornire un suono non pulitissimo ma per il prezzo che ha, svolge la sua funzione abbastanza bene.

This is a preamplifier. It has volume control and tone controls. Bass, midrange, and treble.When I bought it, I thought that I could drive it with a classic DC power supply.Oh boy, I was wrong. This little fella needs to be powered directly from a dual ac transformer. What does that mean? It means that you have to know what you are doing if you want to buy this preamp.You need to know how to connect the aforementioned dual ac power supply, and at the same time double check each of your connections with a multimeter.If you manage to get past that point, its a no noise preamp with quality components. From my little experience I guess the tone controls range from -9db to +9db. Maybe less. But for a fairly flat pair of speakers, that's more than enough.The potentiometers are sturdy.That's all. If you know your way around circuit boards and you'd like to buy a cheap tone controls unit, this is it.

Preamplificatore fantastico dal grande suono.