For this tube preamplifier, we have two versions, with tubes version and without tubes versions, you could choose one of them during the order.
This tube pre-amp use some very welknow tubes, like:
6j4 can be replace directly by europ EF94 tube or US 6AU6
6p6p can be replce directly by 6v6,
The new version has arrived, reduce again the S/N and improve the performence
The unit cheapest preamplifier market, and it\&x27;s one of best preamp, give a best and full frequence finest sound
6j4 + 6p6p + 6z5p preamplifier
Output voltage for 12vPP
Gains: x8
ALPS type16 customed 100K volume Potentiometer
Gold-plated RCA plug.
Frequency response : 10Hz100KHz(0dB)
10Hz200KHz(0.2dB)
SNR: 89db
3 model tubes is: 6j4(2pcs) + 6p6p(2pcs) + 6z5p(1pcs) Shuguang
4 ways inputs, 1 ways output.
Size: 29*17*5CM
Input voltage: 110v, 220v, 230V, 240v version available
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HiFi 6j4+6p6p Class A preamp Tube valve amplifier preamps
NOTI:it\&x27;s preamp without power output. it\&x27;s not an amplifier.so you can not directly connect it to speaker.you need connect it to real power amplifier.
![](https://ae01.alicdn.com/kf/HTB1wpMqKVXXXXblXpXXq6xXFXXXG.jpg)
![](https://ae01.alicdn.com/kf/HTB153aCJFXXXXcTXVXXq6xXFXXXp.jpg)
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With blow plate:![](https://ae01.alicdn.com/kf/HTB1WaMDQVXXXXcDXVXXq6xXFXXXV.jpg)
Use tube amps Precautions:
1. Tube amp must connected with speakers before turning ON. Strictly prohibit send signals to amp without connected loads(speakers) or load short circuit when the switch is ON.
2. Too high or too low power supply voltage does irreversible harm to the amp,preferably less than 5% of the specified voltage. If your mains voltage exceeds this value, often best to use with the AC power supply.
3. Temperature is higher when tube amps working, placing attention to ventilation, cooling.
4. In the boot or just shut down for a period of time (within 30 minutes) Do not spill liquid on the tubes.
5. You should take about 100h time to operate the amp.RUN-IN to the amp gives it\&x27;s best and stable sound.so during the first 100h use time the sound maybe is not the best,you can also use your own run-in method.
Alltube amplifier used with stereo mode: 2 speakers, L and R.
Normally there are 6 RCA outputs are for 2 different impedence which are 4 ohms or 8 ohms than: +8L, +4L, -0L, -0R, +4R, +8R
Example when your speakers are 8 ohms, you plug +8L and -0L for left speaker, -0R and +8R for right .
And for 6 ohms impedence speakers you can plug to either 8 ohms mode or 4 ohms mode.
Some tube amplifier power cable(plug) is not included, because of the electrical outlet format, but you can always use the PC power cable(plug) in 110v- 240v
Shipping time:
Default send by express delivery,about 8-16business days can arrive most of europe countries, Russia, Brazil,Africa.Ukraine and some other remote countries will need some more days.
Return & Exchange:
> Some items return is accepted within 7 days after the buyer&x27;s receiving the item.(please see the detail describe)[In case of DOA (Dead on Arrival), please report within 3 days]
> Returned item has to be new, unworn and in its original condition.
> After getting the returned item, we will refund the customer at the item&x27;s price ( excluding the shipping costs to and from )