The preamps provide up to 40dB of gain. These have close serial #'s 1396 and 1408 and make an excellent matching pair.They employ two 12AY7 (6072) tubes and I went through multiple combinations to get these matched up very closely. The faceplate is all engraved lettering including a vintage Altec logo. Let me know if you have any questions and check out my other vintage pro audio listings. This item is in the category "Musical Instruments & Gear\Pro Audio Equipment\Preamps & Channel Strips". The seller is "shimbuktu" and is located in this country: US. This item can be shipped to United States, Canada.