The TELEFUNKEN 6550-TK is a high output power tube suitable for use in guitar amplifiers and Leslie speaker systems. Ideal for use in classic Marshall, Fender and Ampeg tube circuits, the 6550-TK offers outstanding performance and stability.
Tung-Sol developed the 6550 in 1955 for use as a servo amplifier and in industrial applications. The design is based on the 6L6, but with more gain and better stability.
Like the 6L6, the 6550 is a beam power tube design (or power tetrode) that can painlessly deliver 35 watts at its output.
Any bass player with an Ampeg SVT knows the beauty of the 6550 sound, as well as the raw power they can deliver. One of the best features of the 6550 is the tube’s long life characteristic, which will grant the user fewer tube changes over the years.
We guarantee your tube to be 100% operational! If it is not we will give you a full refund.
At Fuzz Audio, all vintage/NOS vacuum tubes purchased through our website are guaranteed for one year from purchase date. We accept returns for tubes going noisy, losing output/performance prematurely, and of course losing function all together. (Read about power tubes below).
We will not cover damage from red plating neglect, glass breakage of any kind, loose bases, or other obvious faults that are due to neglect, rough handling or egregious constant use.
This policy is meant to protect the buyer from having a tube go out on them prematurely from a flaw we missed. Tubes, especially preamp tubes, should last half a lifetime, and well beyond a year, so we want to guarantee each customer that you get a tube that will last.
For power tubes, although we will honor any faults mentioned above, we will not accept a return for a power tube that has obviously been used for 6+ hours a day for every day of the year for one year. Power tubes that have clearly been used beyond their normal wear point will not be accepted.
If you suspect one of your vintage Fuzz Audio tubes has gone bad within one year of purchasing, simply reach out via our chat or at Support@fuzzaudio.com and we will assist you in the warranty exchange process. No receipt is needed.
Please note, it is possible we will be out of stock of the tube that is in need of a swap. If this is the case, we will either offer a refund, credit, different tube, or send the first available tube of that type when it comes back in stock.
If you have any questions or concerns, please reach out!
At Fuzz Audio:
- We match all tubes for free!
- All vintage tubes are guaranteed for one year.
- All tubes are tested on a calibrated Hickok 539C, Amplitrex, Maxi-Matcher, or other industry standard tube analyzers.
- Preamp tubes are matched by gain and mutual conductance (Gm)
- Power tubes matched by mA and Gm
- All tubes tested for microphonics and are guaranteed to work in your application.
- If you require SUPER LOW noise tubes, please reach out. We will most likely meet your requirements for free.
- Do not hesitate to reach out if you have any questions or concerns, we are here for you.
We guarantee NOS test scores, clean pins, tight matches, and ultimately that they work in your application or YOUR MONEY BACK!
Tubes in photos represent the tube you will receive. Getter construction or logo may differ. Logo may be partially missing or cleaned off. You may or may not receive a box. Tube type, manufacture, and NOS test quality will NOT change. If logos and original boxes are a deal breaker- please reach out before purchase we are always happy to accommodate.
Our policy lasts 30 days. If 30 days have gone by since your purchase, unfortunately we can’t offer you a refund or exchange.
To be eligible for a return, your item must be unused and in the same condition that you received it. It must also be in the original packaging.
- Gift cards
- Downloadable software products
- Some health and personal care items
To complete your return, we require a receipt or proof of purchase.
Please do not send your purchase back to the manufacturer.
There are certain situations where only partial refunds are granted (if applicable)
- Book with obvious signs of use
- CD, DVD, VHS tape, software, video game, cassette tape, or vinyl record that has been opened
- Any item not in its original condition, is damaged or missing parts for reasons not due to our error
- Any item that is returned more than 30 days after delivery
Refunds (if applicable)
Once your return is received and inspected, we will send you an email to notify you that we have received your returned item. We will also notify you of the approval or rejection of your refund.
If you are approved, then your refund will be processed, and a credit will automatically be applied to your credit card or original method of payment, within a certain amount of days.
Late or missing refunds (if applicable)
If you haven’t received a refund yet, first check your bank account again.
Then contact your credit card company, it may take some time before your refund is officially posted.
Next contact your bank. There is often some processing time before a refund is posted.
If you’ve done all of this and you still have not received your refund yet, please contact us at email@example.com.
Sale items (if applicable)
Only regular priced items may be refunded, unfortunately sale items cannot be refunded.
Exchanges (if applicable)
We only replace items if they are defective or damaged. If you need to exchange it for the same item, send us an email at Support@fuzzaudio.com and send your item to: 7901 E Belleview Ave, Apt. 359, Englewood CO 80111, United States.
To return your product, you should mail your product to: 7901 E Belleview Ave, Apt. 359, Englewood CO 80111, United States
You will be responsible for paying for your own shipping costs for returning your item. Shipping costs are non-refundable. If you receive a refund, the cost of return shipping will be deducted from your refund.
Depending on where you live, the time it may take for your exchanged product to reach you, may vary.
If you are shipping an item over $75, you should consider using a trackable shipping service or purchasing shipping insurance. We don’t guarantee that we will receive your returned item.
Payment & Security
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