Tube Purchase Order Form (pdf)


Tube Inventory for Web PDF (pdf)


Vacuum tube sales AND INVENTORY

(Order Form & Inventory/Price Files Above)

Our Tubes

When you buy tubes from Western Glow, you get tubes that have been tested with top-end equipment along with valid, straightforward test results, so you know what you're getting.  We don't use the words "tested good," or "strong," even though all our tubes are good and strong.  You get objective numbers, not vague words. (The noise/microphonics test is subjective.)

All our tubes are screened for measured shorts, heater-to-cathode leakage (unless it’s a directly heated tube) and then tested for gas, emissions, and transconductance (Gm) on an Amplitrex AT1000 (in some cases on a Triplett 3444).  Measurements are compared to published standards and/or Amplitrex database for emissions and transconductance.  

Diode tubes are measured for Forward and Reverse Current.  Full-Wave rectifier tubes (like 5U4, 5Y3, GZ34) are measured for Peak Forward and Reverse Voltage drops for both sections.  All tubes are tested in Fixed Bias mode, which is our default and the mode we consider most valid in general.  

Finally, tubes undergo a noise/microphonics test and rated on a subjective scale.  We then place in a new white box (unless the tube has a vintage box) with the test results affixed to a label on the box top.  For vintage boxes, we put the results label inside.

All Tubes Include Standard Test Data: 

·Emissions New Spec and Actual (New Spec per RCA RC-30 and/or Amplitrex AT1000 database)

·Gm New Spec and Actual (New Spec per RCA RC-30 and/or Amplitrex AT1000 database)

·Gm Actual as % of New

·Gas (In mA. No gas test possible for diode sections.)

·Noise/Microphonics Subjective Scale (Very Low, Low, Moderate) 

Shorts and Heater-to-cathode leakage results are omitted, as any tube with shorts or leakage is automatically rejected.  We sell no tubes with shorts or heater-to-cathode leakage.  Tubes with excessive noise are rejected as well.  Balance for multi-section tubes are rated in the comments field for each tube in the inventory list.  Well-matched tube pairs are noted here, too. 

Our Test Results Grading Scale

69% and below = Rejected, unless a highly desirable tube

70%-74% = Good

75%-84% = Very Good

85% and higher = As New  

While some knowledgeable sources, using old-school manufacturers' standards and statistics, regard 50% of new Gm as the low end of the Good range, we like to stay closer to 70% with common brands and newer vintages.  For more collectible and valuable tubes, such as those from Western Europe and USA made back in the day, we're OK with 50%, especially if those tubes have good cosmetics.

In any case, we sell no tubes with shorts, heater-to-cathode leakage, or excessive noise.  Check the inventory page and the comments for each tube for info on balance and noise if anything is remarkable.

Our Tube Grading System

N1 (New Grade 1)

A new tube in the original box.  Tested but never used.  Perfect cosmetics.  Tests as new (85% and above).

N2 (New Grade 2)

A nearly new tube with light use, often in original box.  Excellent to perfect cosmetics.  Tests as new (85% and above).

N3 (New Grade 3)

A tube that appears nearly new, sometimes in the original box.  Cosmetics are very good to excellent.  Tests as New (85% and above).


U1 (Used Grade 1)

A lightly used tube, sometimes in original box.  Cosmetics very good to excellent.  Tests as New (85% and above).


U2 (Used Grade 2)

A used tube, sometimes in original box.  Cosmetics good to very good.  Tests as Good to Very Good (70% to 84%).

U3 (Used Grade 3)

A used tube in our new, generic box.  Cosmetics good.  Tests as Good to Very Good (70% to 84%).

U4 (Used Grade 4)

A used tube in our new, generic box.  Cosmetics poor to fair.  Tests as Good (70% to 74%).

Again, check the comments on the inventory page, as some tubes vary in some way from these classifications, and those variances are noted. For example, sometimes U3 have correct box or excellent cosmetics.  Some tubes with dual triode sections might be just OK on balance, and this is noted and reflected in pricing.

Matched Sets

When available, matched sets are noted on the inventory page and are within 10% of each other for emissions and 5% of each other for transconductance (Gm).

Ordering, Invoicing & Shipping

Fill out the order form with the link above, scan it or photograph it clearly, and email it to us (  We’ll carefully pack and ship your tubes out the same day we receive your order or the next business day.  We accept Paypal and most credit cards via PayPal (a PayPal account is not required) and will send you an invoice prior to sending your tubes.  We use USPS First Class Package Service.  It's trackable, with delivery six days per week. Best of all, ours is $5 flat rate to the lower 48 states, whether it's one tube or 10!  If you prefer another shipping service (USPS, UPS or FedEx only), indicate on the form. Those services will be billed at actual cost.  

Warranty & Return Information

We want all our customers to be happy and we strive for a fair warranty and return policy.  Please email us right away if you have any problem.

Used tubes can be returned for replacement, not refunds, within 30 days of purchase date if they fail within 30 days of purchase date.  New tubes must be returned within 60 days.  Failure simply means the tube stops working or starts making excessive noise.  Returns for these reasons are not common, as we are quite thorough and careful in our testing, handling, and shipping.  Sorry, we cannot accept returns for any other reason, so please choose your tubes carefully for correct application and confirm suitability with the equipment manufacturer, including manufacturer documentation.  If a tube fails within 30 days of purchase (60 days for new tubes), contact us via email and let us know. We'll decide if the tube needs to be shipped back for replacement.  If we do not have a suitable replacement, we will refund the purchase price, but not the original shipping cost.  Sorry, but we cannot guaranty any tube if broken or damaged from operator error. Again, please choose your tubes carefully.

If we authorize a return, please package your tube carefully and send via a trackable service, insured. Buyer is responsible for return shipping.  We will pay shipping for the replacement to you. Please do not use envelopes unless you first wrap tubes in bubble wrap and then an outer corrugated/cardboard shield.  Best to use a small box and wrap tubes in small bubble wrap, and then provide cushioning all around with crumpled wrapping paper or newspaper.  


Western Glow Tube Service is not liable for any damages (direct, indirect or consequential) arising out of the use of tubes purchased from Western Glow Tube Service.  This includes if a tube failure causes damage to your equipment.  Please choose your tubes carefully for correct application and confirm suitability with the equipment manufacturer, including manufacturer documentation.