{"id":5668,"date":"2016-07-31T13:46:47","date_gmt":"2016-07-31T12:46:47","guid":{"rendered":"http:\/\/www.bartola.co.uk\/valves\/?p=5668"},"modified":"2016-07-31T13:46:47","modified_gmt":"2016-07-31T12:46:47","slug":"dvb-in1166-input-transformer-test","status":"publish","type":"post","link":"https:\/\/www.bartola.co.uk\/valves\/2016\/07\/31\/dvb-in1166-input-transformer-test\/","title":{"rendered":"DvB (IN1166) input transformer test"},"content":{"rendered":"
\"IN1166<\/a>
IN1166 DUT<\/figcaption><\/figure>\n

This is a long overdue post, as I have carried out these tests time ago but never got around to publish the results. Dorin from DvB transformers sent me a pair of his transformers for testing. These are great devices for amp input stages, particularly for a nice Spud amp using medium mu output stages with 6P15P or 6e5P for example. \u00a0Either PP or SE output, this will give you a great solution for a minimalistic design:<\/p>\n

\"post-224566-0-31818400-1441560154\"<\/a><\/p>\n

The configuration options are multiple, you can see what you can do with a similar transformer spec from DvB:<\/p>\n

\"IN1155b_\"<\/a><\/p>\n

I did some tests without any Zobel compensation and here was the initial result:<\/p>\n

\"First<\/a>
First test without Zobel compensation<\/figcaption><\/figure>\n

The nasty peak at 40kHz can be easily corrected by adding a 8k1 resistor in series with a 1,600pF capacitor as Zobel arrangement across the secondary:<\/p>\n

\"With<\/a>
With Zobel compensation<\/figcaption><\/figure>\n

The transformer can do a nice flat response from DC to 40kHz (-3dB) in a 1:6 arrangement as shown above. This is really good.<\/p>\n

The distortion response is really good as well. Let’s have a look at the response of the IN1166 transformer with different input signals. Starting with a 1Vrms output:\"IN1166<\/a><\/p>\n

The third harmonic is higher than the second which is due to the distortion introduced by the transformer. \u00a0However, the overall THD is very low (0.0028%). It’s rather more interesting to see its performance when swinging larger volts. Here is the example at 0.008% for 5Vrms output level<\/p>\n

\"IN1166<\/a><\/p>\n

 <\/p>\n

 <\/p>\n

The response at 10Vrms output level is shown below. The distortion harmonic profile changed with a higher H2 and decaying H3 and H4 which is nice to see. Overall THD is 0.006% @10Vrms which is very nice to see:<\/p>\n

\"IN1166<\/a>Overall, a great and flexible transformer to use in my opinion. A nice cathode follower to drive it to ensure a good HF response due to leakage capacitances in play and the reflection of the Miller capacitance of the output stage into the primary which is the challenge of using a step up transformer in a Spud amp.<\/p>\n

Contact Dorin directly if you want one of this. He can be reached on his email account which is dorin.bodea at gmail.com.<\/p>\n

Ale<\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

This is a long overdue post, as I have carried out these tests time ago but never got around to publish the results. Dorin from DvB transformers sent me a pair of his transformers for testing. These are great devices for amp input stages, particularly for a nice Spud amp using medium mu output stages … Continue reading “DvB (IN1166) input transformer test”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[5],"tags":[927,926,924,928,925],"class_list":["post-5668","post","type-post","status-publish","format-standard","hentry","category-valves","tag-dvb-transformer","tag-in1166","tag-input-transformer","tag-spud-amplifier","tag-tx"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p2r2tK-1tq","jetpack_likes_enabled":true,"jetpack-related-posts":[],"_links":{"self":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/5668","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/comments?post=5668"}],"version-history":[{"count":1,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/5668\/revisions"}],"predecessor-version":[{"id":5677,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/posts\/5668\/revisions\/5677"}],"wp:attachment":[{"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/media?parent=5668"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/categories?post=5668"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bartola.co.uk\/valves\/wp-json\/wp\/v2\/tags?post=5668"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}