Category: Tube FAQ & Must Read

What’s the sound when I turn on the tubes?

Some tubes at start up will have a metal like sound from inside the tube. This is the plate materials being heated up and expand – this sound will disappear once the tube is turned on for a few minutes.

Such a sound will happen at each time you turn on the tube – i.e. at each heat up process. This is perfectly normal and it doesn’t indicate bad tube quality or whatsoever. It’s a natural process of metal expanding under extreme heat.

Some tubes have this sound, others don’t because each type / make of tube might be using different plate materials.

Why my tube box isn’t in perfect shape?

Well, we audiophiles live on perfection but sometimes it’s hard to achieve. We make every efforts to make our tubes as high quality as we can, but sometimes the tube package boxes get damaged in wholesale shipping due to rough handling.

We do not stock extra boxes in warehouses as all tubes are air shipped from factory. Shipping an empty box will cost the same as we ship a box with products in it. To maintain cost effective on all products, we try to eliminate the unnecessary expenses and use the funds to source great products for audiophiles.

If you get a tube box with latch missing or slight wear and tear, we ask your kind understanding of the international shipping challenges and we hope to service you better next time.

We never cut corners on tube quality, but sometimes the box corners might be cut unintentionally 🙂 Thank you for your kind understanding.

Do you offer matched quad?

In a short answer, yes. But there is extra shipping charges for re-directing the order to ship from Canada instead of our usual tube shipping warehouse in Hong Kong. The extra shipping charges is to cover shipping from Canada to the buyer – our free shipping offer only covers the first leg of the tube shipping (from Hong Kong to Canada for matching).

Please add a note in your order if you do need matched quad. We will check our inventory and let you know if we have them readily available. There is no extra charge for providing matched quad but availability will be depending on stock.

Do you need matched quad?

For power tubes (such as 845/211/805) without manual biasing, you should always try to get matched quad. If not possible, you should split each pair for both channels – i.e. if two pairs of tubes are 1A, 1B, 2A and 2B. Use 1A and 2A on the left channel; 1B and 2B on the right channel (same order as left). This way you will get your stereo perform as balanced as possible.

Most high voltage tube amps using 845, 805 and 211 have manual biasing.

For preamp tubes, follow the same rules as above when using matched pairs instead of matched quad.

I am a tube vendor, can I order at wholesale price?

At this time, we do not sell to online tube vendors.

If you are a tube amp manufacturer, we can provide OEM price for factory matched pairs only. Please provide your business license information and use the contact form to contact us directly for a quotation. Minimum quantity applies to commercial orders.

All sample orders are at regular retail price – once you are satisfied with the quality, you can proceed with a commercial order then we will retro-apply the discount to your sample order in your new invoice.

Thank you for your understanding.

What is this sticker on the tube?

Some tubes have a numbered metal foil or paper sticker on them. These numbers are not the testing results – they are numbers used to identify each tube during the matching process. It has no meaning to tube users and we usually remove them when we ship the orders. Sometimes warehouse may omit this step during order processing.

If you find your newly purchased Psvane (Pavane) tubes have this numbered sticker on them, please remove it before installing the tube into your amplifier. If there is residual glue on the tube glass, you can use damp cloth to wipe the glue off. Do not wet the tube itself in any liquid.

What kills a vacuum tube?

The single biggest factor is the voltage added to the tube plate (anode). You cannot control the electron emission from the cathode (this is determined by the tube cathode material and tube age), so if the plate voltage is too high, the heat generated by electrons hitting the plate cannot be dissipated fast enough, which will cause a ‘red plate’. This usually happens on power tubes, not on preamp tubes.

To observe if a tube has ‘red plate’, turn off the room light at night and compare the color of the plates to other same kind of tubes. If one is obviously brighter than others, you should check the bias voltage (plate voltage). Adjust it until the tube is not showing red plate and within the amp manufacturer’s suggested bias range.

Do not bias more than 15% below the suggested bias voltage provided by the amp manufacturer – this will cause the tube not operating at optimal condition and will in fact shorten tube life.

Some amplifiers are designed with the tubes running with plate voltage higher than others – we suggest you follow the amp manufacturer’s recommendation.

Why some tube flash when turn on?

This usually happens on smaller preamp tubes – the flash is from the heater when power on, and it only last a split of second then disappear. This is normal on tubes and happen randomly. It doesn’t short the tube life and will not affect the sound.

Some great vintage tubes made in 1950’s have the same flash and they lasted for over 40 years!

Why are tubes primarily graded by emission?

Vacuum tube works with cathode (an internal structure which is heated at extremely high temperature to emit electrons) to generate electron flow – i.e. electron current, which is usually measured in mA (number of electrons flow through per second). This is the most important indicator of tube life.

Strong emission = longer tube life. Weak emission = shorter tube life.

Strong emission also means that the tube will perform in the circuit closer to the equipment’s designed specification.

With time, all tubes will have weaker and weaker emission, until eventually they cannot perform adequately in a live circuit.

Other factors will also affect tube life such as vacuum leakage, heater to cathode leaker or internal gas.