Ruby Tubes

Our tube finder gives you a kit with every tube your amp takes, laid out by position. Can't find your amp? Send us the make and model and we'll tell you exactly what goes where. Find tubes for your amp

Every preamp, power and rectifier tube your amp model takes, with the power tubes matched. You pick the brand, like JJ, RUBY, Mullard or Tung-Sol (brands vary by kit). A kit costs the same as buying each tube on its own, with no kit markup. Shop tube kits

Preamp tubes like the 12AX7 and 12AT7 shape gain and tone. Power tubes like the 6L6, EL34, EL84, 6V6 and KT88 drive the speaker and set volume and headroom. Rectifier tubes like the 5AR4 and 5Y3 turn wall power into the DC your amp runs on and control how much it sags. See the tube substitution chart

Only for power tubes in a fixed-bias amp. Cathode-biased amps, like most EL84 combos and many 6V6 amps, set themselves, and preamp tubes never need biasing. Amps hold lethal voltage even when unplugged, so have a qualified amp tech do it.

Power tubes wear out first. If you gig a lot, plan on new ones every year or two. Preamp tubes can last many years. Replace any tube that gets noisy, microphonic or weak. Learn how to test your tubes

Every tube is burned in first, then bench tested on its own for noise and microphonics. Power tubes are then matched by plate current and transconductance and graded, so pairs and quads share the load evenly. Tubes that don't meet spec don't ship. See our full testing process

No. Burn-in, testing and matching are included on every tube at no extra cost.

They're our gain grades on RUBY 12AX7s. HG is our standard high-gain rating for high-gain circuits. HG+ is a premium grade with extra-close transconductance.

Every tube we sell has a 6-month warranty. If a tube fails from a defect within six months, we'll replace it. If that tube isn't available, we'll send a comparable one or give you store credit. Start a warranty claim

You have 30 days after delivery to request a return. Items must be unused, in their original packaging, with proof of purchase. Contact us before sending anything back, since returns sent without approval aren't accepted. Return shipping is paid by the customer. Used items (unless defective), gift cards, custom items including amp coverings, and special orders can't be returned. Approved refunds go back to your original payment method within 10 business days. Read our full refund policy

Email orders@magicparts.com right away with your order number and photos of the item and the box. If you added Shipping Protection at checkout, send photos within 7 days of delivery and we'll replace or refund lost, stolen or damaged packages.

Yes. U.S. orders over $125 ship free (oversized items like amps and cabinets, plus some heavy items like grill cloth and tolex, are excluded). And every Tuesday through the end of 2026 is Ruby Tubesday: free U.S. shipping on all vacuum tubes and tube kits. Read about Ruby Tubesday

Most orders ship within 1–2 business days from our shop in California. You'll get a tracking link by email as soon as your order ships. Transit time depends on where you are.

Yes, worldwide, including P.O. boxes and APO/FPO/DPO addresses. Shipping cost is calculated at checkout. Customs fees, duties and import taxes are paid by the customer.

No. One code per order, and codes can't be combined with other offers or sale prices unless we say so. Some products are excluded from promotions.

Yes, for amp techs, repair shops, builders and retailers, with no minimum order. We usually approve accounts within 1–2 business days, and net terms are available to established accounts on request. Apply for a wholesale account

Email orders@magicparts.com or call (800) 451-1922, Monday through Friday. Send us your amp model and we'll help you pick the right tubes.